NASA Considers Sending a Telescope to the Outer Solar System
ZEBRA (Zodiacal dust, Extragalactic Background and Reionization Apparatus) is a small, passively cooled optical to near-infrared instrument package that could be added to an outer solar system probe. Credit: NASA/JPL/Caltech
Editors note — Science journalist and author Bruce Dorminey spoke to two NASA scientists about the possibility of mounting a telescope on a spacecraft for an outer planets mission.
Light pollution in our inner solar system, from both the nearby glow of the Sun and the hazy zodiacal glow from dust ground up in the asteroid belt, has long stymied cosmologists looking for a clearer take on the early Universe.
But a team at NASA, JPL and Caltech has been looking into the possibility of hitching an optical telescope to a survey spacecraft on a mission to the outer solar system.
(…)
Read the rest of NASA Considers Sending a Telescope to the Outer Solar System (1,269 words)
© Bruce Dorminey for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: Extragalactic Background and Reionization Apparatus, Missions, NASA, ZEBRA (Zodiacal dust
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Special Relativity From First Principles
There’s hope for us all if a mild-mannered patent office clerk can become Person Of The 20th Century.
Einstein’s explanation of special relativity, delivered in his 1905 paper On the Electrodynamics of Moving Bodies focuses on demolishing the idea of ‘absolute rest’, exemplified by the theoretical luminiferous aether. He achieved this very successfully, but many hearing that argument today are left puzzled as to why everything seems to depend upon the speed of light in a vacuum.
Since few people in the 21st century need convincing that the luminiferous aether does not exist, it is possible to come at the concept of special relativity in a different way and just through an exercise of logic deduce that the universe must have an absolute speed – and from there deduce special relativity as a logical consequence.(…)
Read the rest of Astronomy Without A Telescope – Special Relativity From First Principles (585 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: special relativity
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Could Dark Matter Not Matter?
Rotation curves of the Andromeda Galaxy. Actual rotational velocities of the outer stars are the white line, while velocities that would be expected from the estimated mass of the visible matter in the galaxy are the red line. Hence, we conclude that over 80% of the galaxy’s mass must be dark matter. (Credit Queens Uni.).
You probably want to put on your skeptical goggles and set them to maximum for this one. An Italian mathematician has come up with some complex formulae that can, with remarkable similarity, mimic the rotation curves of spiral galaxies without the need for dark matter.
Currently, these galactic rotation curves represent key evidence for the existence of dark matter – since the outer stars of spinning galaxies often move around a galactic disk so fast that they should fly off into intergalactic space – unless there is an additional ‘invisible’ mass present in the galaxy to gravitationally hold them in their orbits.(…)
Read the rest of Astronomy Without A Telescope – Could Dark Matter Not Matter? (732 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
One comment |
Add to
del.icio.us
Post tags: galaxy rotation curves
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – The Progenitor Problem
DEM L71 – a Type 1a supernova remnant. Analysis of the outer shockwave and inner ejecta indicate the remnant material does not greatly exceed 1 solar mass – and it contains a high iron to silicon/oxygen ratio. This all suggests that the progenitor star was a compact white dwarf. But, apart from that, the steps that led up to the explosion are a mystery (Credit: NASA/Chandra).
With so much of our current understanding of the universe based on Type 1a supernovae data, a good deal of current research is focused upon just how standard these supposed standard candles are. To date, the weight of analysis seems reassuring – apart from a few outliers, the supernovae do all seem very standard and predictable.
However, some researchers have come at this issue from a different perspective by considering the characteristics of the progenitor stars that produce Type 1a supernovae. We know very little about these stars. Sure, they are white dwarfs that explode after accumulating extra mass – but just how this outcome is reached remains a mystery.(…)
Read the rest of Astronomy Without A Telescope – The Progenitor Problem (520 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: Type 1a supernovae progenitor
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Mass Is Energy
The USS Enterprise in 1964 (pre Zefram Cochrane era), during Operation Sea Orbit when it sailed around the world in 65 days without refuelling – demonstrating the capability of nuclear-powered ships. Credit: US Navy.
Some say that the reason you can’t travel faster than light is that your mass will increase as your speed approaches light speed – so, regardless of how much energy your star drive can generate, you reach a point where no amount of energy can further accelerate your spacecraft because its mass is approaching infinite.
This line of thinking is at best an incomplete description of what’s really going on and is not a particularly effective way of explaining why you can’t move faster than light (even though you can’t). However, the story does offer some useful insight into why mass is equivalent to energy, in accordance with the relationship e=mc2.(…)
Read the rest of Astronomy Without A Telescope – Mass Is Energy (740 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: energy-mass equivalence
Feed enhanced by Better Feed from Ozh
Live Webcast as Keck Telescope Attempts Images of Asteroid 2005 YU55
Astronomers from the Keck Telescope in Hawaii will be trying to observe Asteroid 2005 YU55 as it flies away from Earth. A live webcast from Keck starts about the same time this article is being published, starting no later than 9 pm U.S. PST on Nov. 8, or Midnight EST/ 0500 UT on Wednesday, Nov. 9. Indications are the webcast might start a little late because of fog on Mauna Kea.
Their hope is to get infrared images and perhaps a three-dimensional view of the asteroid with one of the world’s largest optical/infrared telescopes. The observing run is being webcast live on UStream from the Keck II Remote Operations room in Kamuela, Hawaii. They also are hoping to be able to look for moons around the asteroid. About 20% of asteroids have “moons” orbiting them.
At the helm of the 10-meter Keck II telescope and using Keck’s pioneering adaptive optics to view YU55 will be asteroid investigators William Merline and Peter Tamblyn of Southwest Research Institute, in Boulder, Colorado, and Chris Neyman of Keck Observatory.
© nancy for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: Asteroid 2005 YU55, Asteroids, Keck Telescope
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Flat Universe
Various universe evolution scenarios. A universe with too much density collapses in on itself, a critical density universe stays static, while a universe with not enough density keeps expanding at a steady (coasting) rate. However, today’s cosmology puts emphasis upon the cosmological constant, which gives an accelerating expansion. Does this mean that density is irrelevant? Credit: NASA.
A remarkable finding of the early 21st century, that kind of sits alongside the Nobel prize winning discovery of the universe’s accelerating expansion, is the finding that the universe is geometrically flat. This is a remarkable and unexpected feature of a universe that is expanding – let alone one that is expanding at an accelerated rate – and like the accelerating expansion, it is a key feature of our current standard model of the universe.
It may be that the flatness is just a consequence of the accelerating expansion – but to date this cannot be stated conclusively.(…)
Read the rest of Astronomy Without A Telescope – Flat Universe (687 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: Einstein field equations
Feed enhanced by Better Feed from Ozh
Thinking of buying a telescope?
Selecting a telescope, like buying a car, is subject to your tastes as a consumer. In other words, the choice is up to you. But the editors at Astronomy magazine have just made that decision a lot easier with “How to Buy Your First Telescope.” This 16-page pluck-out guide sponsored by Celestron appears in the November 2011 issue of Astronomy, on newsstands now.
After reading this goldmine of information, you’ll be able to identify the main types of telescopes (and the advantages of each one), tell the difference between computerized and manual mounts, and select the proper eyepieces and accessories. You’ll also read about getting started as an amateur astronomer. In fact, we’ll even help you target appropriate objects in the sky.
In short, this guide provides everything you need so you can make your first telescope purchase as informed as possible. Thanks to the folks at Celestron for their input and for helping make this 16-page booklet a valuable resource for budding amateur astronomers.
Astronomy Without A Telescope – Light Speed
You could cross the universe in a matter of hours without ever 'breaking light speed' – it is not the speed limit that it seems to be.
The recent news of neutrinos moving faster than light might have got everyone thinking about warp drive and all that, but really there is no need to imagine something that can move faster than 300,000 kilometres a second. Indeed, the whole idea is illogical.
Light speed, or 300,000 kilometres a second, might seem like a speed limit, but this is just an example of 3 + 1 thinking – where we still haven’t got our heads around the concept of four dimensional space-time and hence we think in terms of space having three dimensions and think of time as something different.(…)
Read the rest of Astronomy Without A Telescope – Light Speed (671 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: faster than light travel, relativity
Feed enhanced by Better Feed from Ozh
World’s most powerful millimeter/submillimeter-wavelength telescope opens for business and reveals its first image
Astronomy Magazine News Article – Released:10/4/2011
Astronomy.com News – Presented by Astronomy Magazine
NASA space telescope finds fewer mid-size range asteroids near Earth
Astronomy Magazine News Article – Released:9/30/2011
Astronomy.com News – Presented by Astronomy Magazine
ESO’s Very Large Telescope captures rare look at a hypergiant star
Astronomy Magazine News Article – Released:9/28/2011
Astronomy.com News – Presented by Astronomy Magazine
On the road: The 2011 Pacific Astronomy and Telescope Show, Day 2
Yesterday, Sunday, September 18, was the last day of the fourth annual Pacific Astronomy and Telescope Show (PATS) in Pasadena, California. One of the conference’s organizers told me that Saturday was the best day (attendance-wise) in the 4-year history of the event.
Since I’ve been here, I’ve seen several products you’ll be reading reviews of in upcoming issues of Astronomy magazine. And I’ve talked to other manufacturers who promised announcements of new gear soon.
Yesterday I gave my talk, “How to Buy Your First Telescope,” to a group of less than 30 people. That number, although disappointing, wasn’t unexpected because the planners scheduled me to speak before noon. Despite the low attendance, we ran out of time at the end because of the number of questions people asked. They were definitely listening.
I’ll be back in the office Tuesday getting ready for my next trip — a star party in Jacksonville, Florida, October 7 to 8, organized by Astronomy Contributing Editor Mike Reynolds. I’ll give a couple of talks and participate in all nighttime public observing sessions. And I’ll be blogging and tweeting. Sounds like fun!
For more on the 2011 PATS show, click here.
On the road: The 2011 Pacific Astronomy and Telescope Show, Day 1
It’s that time of year again. I’m in Pasadena, California, spending the weekend (September 16–18) at the fourth annual Pacific Astronomy and Telescope Show (PATS). This gathering gives telescope and astronomy equipment manufacturers the chance to show off to lots of visitors (many of whom are nurturing their first love of our hobby) the chance to look at and discuss the latest astronomy gear. The newest telescopes, mounts, cameras, eyepieces, and accessories are all on display this weekend. And staffing each booth are salespeople and designers ready and eager to impart their knowledge to interested visitors.
I arrived a day early to talk to manufacturers (mostly as they’re setting up their booths) before the crush of the weekend crowd eliminated detailed conversations. I’m representing Astronomy magazine (one of the show’s sponsors) as the editor most involved in hobby and equipment stories, so I’ve been eager to learn (and report) what’s hot. But I’m also giving a talk. Because the organizers of PATS aim the get-together at the general public, I’ve chosen "How to Buy Your First Telescope" as my topic. The subject matter is near and dear to me, having helped create a special 16-page booklet by the same name Astronomy readers will find included as part of our November issue. I’m on the schedule for 11:45 a.m. today.
Saturday was the first “public day.” About 65 participants met to hear talks by leading astroimagers at the Riverside AstroImaging Workshop (RAW), which always meets the day before PATS. Speakers included Astronomy magazine image contributors Rogelio Bernal Andreo, Ken Crawford, R. Jay GaBany, and Warren Keller. Topics covered ranged from astrophotography for beginners to advanced imaging. Some highlights were “Planning Your Imaging Session,” “Choosing the Right Equipment,” and “Advanced Photoshop Techniques.”
I also walked the PATS floor Saturday. Just in the first few hours, I had great conversations with several manufacturers. And I saw new telescopes and accessories by Celestron, Meade, Quantum Scientific Imaging, and Tele Vue, to name a few.
Of the 38 booths I counted, there’s a mix of equipment manufacturers, astronomy clubs, and organizations supporting professional observatories.
Stay tuned for more blogs and tweets.
P.S. Good thing PATS isn’t a star party. Although the temperature is nice, the California sky is totally cloudy today.
P.P.S. Funny times at the registration desk: Astronomy magazine is a sponsor, we have a booth set up, and I’m speaking tomorrow, but the organizers of PATS didn’t have a name badge for me. I had to print my own. Good thing I was wearing my staff shirt!
Astronomy Without A Telescope – New Physics?
The Sun can affect a lot of things on Earth – but the rate of radioactive decay isn’t normally considered to be one of those things. Credit: NASA.
Radioactive decay – a random process right? Well, according to some – maybe not. For several years now a team of physicists from Purdue and Stanford have reviewed isotope decay data across a range of different isotopes and detectors – seeing a non-random pattern and searching for a reason. And now, after eliminating all other causes – the team are ready to declare that the cause is… extraterrestrial.
OK, so it’s suggested to just be the Sun – but cool finding, huh? Well… maybe it’s best to first put on your skeptical goggles before reading through anyone’s claim of discovering new physics.(…)
Read the rest of Astronomy Without A Telescope – New Physics? (561 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
9 comments |
Add to
del.icio.us
Post tags: variable radioactive decay
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Cosmic Coincidence
The standard model of the universe has it that the energy density of its contents and the ‘dark energy’ of its expansion are, just now, of the same order of magnitude. Coincidence? Credit: NASA.
Cosmologists tend not to get all that excited about the universe being 74% dark energy and 26% conventional energy and matter (albeit most of the matter is dark and mysterious as well). Instead they get excited about the fact that the density of dark energy is of the same order of magnitude as that more conventional remainder.
After all, it is quite conceivable that the density of dark energy might be ten, one hundred or even one thousand times more (or less) than the remainder. But nope, it seems it’s about three times as much – which is less than ten and more than one, meaning that the two parts are of the same order of magnitude. And given the various uncertainties and error bars involved, you might even say the density of dark energy and of the more conventional remainder are roughly equivalent. This is what is known as the cosmic coincidence.(…)
Read the rest of Astronomy Without A Telescope – Cosmic Coincidence (556 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
9 comments |
Add to
del.icio.us
Post tags: cosmic coincidence
Feed enhanced by Better Feed from Ozh
James Webb Space Telescope Nearing Completion
The James Webb Space Telescope, while nearing completion, is facing cancellation by Congress. Image Credit: NASA
The James Webb Space Telescope or JWST has long been touted as the replacement for the Hubble Space Telescope. The telescope is considered to be the one of the most ambitious space science projects ever undertaken – this complexity may be its downfall. Cost overruns now threaten the project with cancellation. Despite these challenges, the telescope is getting closer to completion. As it stands now, the telescope has served as a technical classroom on the intricacies involved with such a complex project. It has also served to develop new technologies that are used by average citizens in their daily lives.(…)
Read the rest of James Webb Space Telescope Nearing Completion (704 words)
© Jason Rhian for Universe Today, 2011. |
Permalink |
6 comments |
Add to
del.icio.us
Post tags:
Feed enhanced by Better Feed from Ozh
The Very Large Telescope looks into The Eyes of Virgo
Astronomy Magazine News Article – Released:8/24/2011
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Why The LHC (Still) Won’t Destroy The Earth
Concerns about a 'big science machine' destroying the Earth have been around since the steam engine. The LHC is the latest target for such conspiracy theories. Credit: CERN.
Surprisingly, rumors still persist in some corners of the Internet that the Large Hadron Collider (LHC) is going to destroy the Earth – even though nearly three years have passed since it was first turned on. This may be because it is yet to be ramped up to full power in 2014 – although it seems more likely that this is just a case of moving the goal posts, since the same doomsayers were initially adamant that the Earth would be destroyed the moment the LHC was switched on, in September 2008.
The story goes that the very high energy collisions engineered by the LHC could jam colliding particles together with such force that their mass would be compressed into a volume less than the Schwarzschild radius required for that mass. In other words, a microscopic black hole would form and then grow in size as it sucked in more matter, until it eventually consumed the Earth.
Here’s a brief run-through of why this can’t happen.(…)
Read the rest of Astronomy Without A Telescope – Why The LHC (Still) Won’t Destroy The Earth (799 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: large hadron collider
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Cubic Neutrons
The currently popular analogy to describe the density of matter within a neutron star is that it’s like compressing the entire human population into a sugar cube. And speaking of cubes… Credit: E. Galactica.
The nature of the highly compressed matter that makes up neutron stars has been the subject of much speculation. For example, it’s been suggested that under extreme gravitational compression the neutrons may collapse into quark matter composed of just strange quarks – which suggests that you should start calling a particularly massive neutron star, a strange star.
However, an alternate model suggests that within massive neutron stars - rather than the neutrons collapsing into more fundamental particles, they might just be packed more tightly together by adopting a cubic shape. This might allow such cubic neutrons to be packed into about 75% of the volume that spherical neutrons would normally occupy.(…)
Read the rest of Astronomy Without A Telescope – Cubic Neutrons (440 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: Neutron Stars
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Impact Mitigation
The Don Quijote mission, which may launch by 2015. The Sancho spacecraft will orbit an asteroid, collecting data as another spacecraft Hidalgo collides with that asteroid, in an attempt to alter its trajectory. Credit: ESA.
The save-the-Earth rehearsal mission Don Quijote, commissioned by the European Space Agency, is planned to test the potential of a real life-or-death mission to deflect a mass-extinction-inducing asteroid from a collision course with Earth.
Currently at ‘concept’ stage, the Don Quijote Near Earth Asteroid Impact Mitigation Mission – has been modelled on a proposed flight to either 2002 AT4 or 1989 ML, both being near-Earth asteroids, though neither represent an obvious collision risk. However, subsequent studies have proposed that Amor 2003 SM84 or even 99942 Apophis may be more suitable targets. After all, 99942 Apophis does carry a marginal (1 in 250,000) risk of an Earth impact in 2036.(…)
Read the rest of Astronomy Without A Telescope – Impact Mitigation (727 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
3 comments |
Add to
del.icio.us
Post tags: Don Quijote
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – A Photon’s Point Of View
The way Hollywood envisions moving at light speed doesn't really work – since it still implies that you move a certain distance over a certain time period. As far as a photon is concerned, it does neither. Source: zidbits.
From a photon’s point of view, it is emitted and then instantaneously reabsorbed. This is true for a photon emitted in the core of the Sun, which might be reabsorbed after crossing a fraction of a millimetre’s distance. And it is equally true for a photon that, from our point of view, has travelled for over 13 billion years after being emitted from the surface of one of the universe’s first stars.
So it seems that not only does a photon not experience the passage of time, it does not experience the passage of distance either. But since you can’t move a massless consciousness at the speed of light in a vacuum, the real point of this thought experiment is to indicate that time and distance are just two apparently different aspects of the same thing. (…)
Read the rest of Astronomy Without A Telescope – A Photon’s Point Of View (474 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
42 comments |
Add to
del.icio.us
Post tags: Space-time curvature
Feed enhanced by Better Feed from Ozh
Herschel telescope detects oxygen molecules in space
Astronomy Magazine News Article – Released:8/2/2011
Astronomy.com News – Presented by Astronomy Magazine
New Webb Telescope Technologies Already Helping Human Eyes
Image of the Scanning Shack Hartmann System (SSHS), a pair of large mirror test stations used to measure the mirror segments of the Webb telescope. As part of that SSHS program, several improvements were made to the wavefront sensor technology that now allow eye health instruments to be aligned more precisely. Credit: Abbott Medical Optics Inc.
Editor’s note: This NASA press release provides just one example of how developing technology for space missions often has practical, beneficial and sometimes unintended applications on Earth.
Even while construction of the James Webb Space Telescope is underway on the most advanced infrared vision of any space observatory, its technologies are already proving useful to human eye health here on Earth.
“The Webb telescope program has enabled a number of improvements in measurement technology for astronomy, mirror fabrication, and measurement of human eyes, diagnosis of ocular diseases and potentially improved surgery,” said Dr. Dan Neal, Research Fellow at Abbott Medical Optics Inc. in Albuquerque, N.M.
(…)
Read the rest of New Webb Telescope Technologies Already Helping Human Eyes (456 words)
© nancy for Universe Today, 2011. |
Permalink |
3 comments |
Add to
del.icio.us
Post tags: James Webb Space Telescope, Technology
Feed enhanced by Better Feed from Ozh
New ESO telescope looks at the Leo Triplet — and beyond
Astronomy Magazine News Article – Released:7/27/2011
Astronomy.com News – Presented by Astronomy Magazine
The Hubble Space Telescope discovers another moon around Pluto
Astronomy Magazine News Article – Released:7/20/2011
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Gravitational Waves
An artist's impression of gravitational waves. In reality, a single uniform massive object does not generate gravitational waves. However, a massive binary system in orbital motion, could generate dynamic pulses of gravitational energy that might be detected from Earth. Credit: NASA.
Gravitational waves have some similar properties to light. They move at the same speed in a vacuum – and with a certain frequency and amplitude. Where they differ from light is that they are not scattered or absorbed by matter, in the way that light is.
Thus, it’s likely that primordial gravitational waves, that are speculated to have been produced by the Big Bang, are still out there waiting to be detected and analyzed.(…)
Read the rest of Astronomy Without A Telescope – Gravitational Waves (761 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: gravitational waves; LIGO
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Granularity
A gamma ray burst is an opportunity to assess the nature of the apparent 'empty space' vacuum that exists between you and it. In GRB 041219A's case, that's 300 million light years of vacuum. Credit: ESA.
The very small wavelength of gamma ray light offers the potential to gain high resolution data about very fine detail – perhaps even detail about the quantum substructure of a vacuum – or in other words, the granularity of empty space.
Quantum physics suggests that a vacuum is anything but empty, with virtual particles regularly popping in and out of existence within Planck instants of time. The proposed particle nature of gravity also requires graviton particles to mediate gravitational interactions. So, to support a theory of quantum gravity we should expect to find evidence of a degree of granularity in the substructure of space-time.(…)
Read the rest of Astronomy Without A Telescope – Granularity (514 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
5 comments |
Add to
del.icio.us
Post tags: quantum gravity theory
Feed enhanced by Better Feed from Ozh
Hubble Space Telescope makes one-millionth science observation
Astronomy Magazine News Article – Released:7/6/2011
Astronomy.com News – Presented by Astronomy Magazine
Subaru 8-meter Telescope Damaged by Leaking Coolant
Orange-colored coolant covers the mirror surface of the Subaru Telescope. Credit: National Astronomical Observatory of Japan
A “serious hardware incident” has shut down the Subaru Telescope indefinitely. A leak allowed orange-colored coolant to spill over the primary mirror and into the main camera, as well as into other instruments and the structure of the telescope. The damage is still be assessed. During the clean-up and recovery of equipment, nighttime observations have been suspended, as well as daytime summit tours of the telescope.
(…)
Read the rest of Subaru 8-meter Telescope Damaged by Leaking Coolant (257 words)
© nancy for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: Observatories, Subaru Telescope
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Big Rips And Little Rips
The concept of accelerating expansion does get you wondering just how fast the universe can end up expanding by. Theorists think that the rate of expansion might become so extreme as to produce a Big Rip. Or, after fiddling with the math a bit, maybe just a Little Rip? Credit: NASA.
One of a number of seemingly implausible features of dark energy is that its density is assumed to be constant over time. So, even though the universe expands over time, dark energy does not become diluted, unlike the rest of the contents of the universe.
As the universe expands, it seems that more dark energy appears out of nowhere to sustain the constant dark energy density of the universe. So, as times goes by, dark energy will become an increasingly dominant proportion of the observable universe – remembering that it is already estimated as being 73% of it.(…)
Read the rest of Astronomy Without A Telescope – Big Rips And Little Rips (594 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: big rip
Feed enhanced by Better Feed from Ozh
Pan-STARRS telescope spots new distant comet
Astronomy Magazine News Article – Released:6/20/2011
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Star Seeds
The Rho Ophiuchi cloud complex – within which the cloud L1688 is the most active star-forming location. Although hidden by dust, it is possible to study star formation by sub-millimetre astronomy. Credit NASA.
Molecular clouds are called so because they have sufficient density to support the formation of molecules, most commonly H2 molecules. Their density also makes them ideal sites for new star formation – and if star formation is prevalent in a molecular cloud, we tend to give it the less formal title of stellar nursery.(…)
Read the rest of Astronomy Without A Telescope – Star Seeds (518 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
2 comments |
Add to
del.icio.us
Post tags: sub-millimetre astronomy
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Oh-My-God Particles
Centaurus A – one of the closest galaxies with an active galactic nucleus – although it is over 10 million light years away. If you are looking for a likely source of ultra-high-energy cosmic rays – you may not need to look further. Credit: ESO.
Cosmic rays are really sub-atomic particles, being mainly protons (hydrogen nuclei) and occasionally helium or heavier atomic nuclei and very occasionally electrons. Cosmic ray particles are very energetic as a result of them having a substantial velocity and hence a substantial momentum.
The Oh-My-God particle detected over Utah in 1991 was probably a proton traveling at 0.999 (and add another 20 x 9s after that) of the speed of light and it allegedly carried the same kinetic energy as a baseball traveling at 90 kilometers an hour.(…)
Read the rest of Astronomy Without A Telescope – Oh-My-God Particles (641 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: cosmic rays
Feed enhanced by Better Feed from Ozh
The European Southern Observatory’s Very Large Telescope finds a brilliant but solitary superstar
Astronomy Magazine News Article – Released:5/25/2011
Astronomy.com News – Presented by Astronomy Magazine
LOFAR telescope makes deeper images of universe than ever before
Astronomy Magazine News Article – Released:6/2/2011
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Holographic Dark Information Energy
The bubble nebula NGC 7635 – it doesn't have a lot to do with Holographic Dark Information Energy, but you have to start these articles with an image. Credit: Croman/an APOD for November 7 2005.
Holographic Dark Information Energy gets my vote for the best mix of arcane theoretical concepts expressed in the shortest number of words – and just to keep it interesting, it’s mostly about entropy.(…)
Read the rest of Astronomy Without A Telescope – Holographic Dark Information Energy (630 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: entropy, Landauer’s principle
Feed enhanced by Better Feed from Ozh
Hubble Space Telescope finds rare “blue straggler” stars in the Milky Way’s hub
Astronomy Magazine News Article – Released:5/26/2011
Astronomy.com News – Presented by Astronomy Magazine
The Hubble Space Telescope views the star that changed the universe
Astronomy Magazine News Article – Released:5/24/2011
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Small Bangs
Gamma-ray bursts. We tend to think of them as big explosions – but it has been suggested that they might actually be Small Bangs. Credit: NASA.
Most gamma-ray bursts come in two flavors. Firstly, there are long duration bursts which form in dense star-forming regions and are associated with supernovae – which would understandably generate a sustained outburst of energy. The technical definition of a long duration gamma-ray burst is one that is more than two seconds in duration – but bursts lasting over a minute are not unusual.
Short duration gamma-ray bursts more often occur in regions of low star formation and are not associated with supernovae. Their duration is technically less than 2 seconds, but a duration of only a few milliseconds is not unusual. These are assumed to result from collisions between massive compact objects – perhaps neutron stars or black holes – producing a short, sharp outburst of energy.
But there are also rare instances of gamma-ray bursts that don’t really fill either category. (…)
Read the rest of Astronomy Without A Telescope – Small Bangs (589 words)
© Steve Nerlich for Universe Today, 2011. |
Permalink |
5 comments |
Add to
del.icio.us
Post tags: GRB 060614, white holes
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Planet Spotting
The current search area of the Kepler mission, monitoring 145,000 stars for signs of exoplanets – with a particular interest in those that may be in a star’s ‘habitable zone’. Credit: Lomberg/NASA.
The Extrasolar Planets Encyclopedia counted 548 confirmed extrasolar planets at 6 May 2011, while the NASA Star and Exoplanet Database (updated weekly) was today reporting 535. These are confirmed findings and the counts will significantly increase as more candidate exoplanets are assessed. For example, there were the 1,235 candidates announced by the Kepler mission in February, including 54 that may be in a habitable zone.
So what techniques are brought to bear to come up with these findings? (…)
Read the rest of Astronomy Without A Telescope – Planet Spotting (895 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us
Post tags: exoplanet detection, Extrasolar Planets Encyclopedia
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Our Unlikely Solar System
A circumstellar disk of debris around a matured stellar system may indicate that Earth-like planets lie within – since such a disk results from the collisional grinding of rocky planetesimals. Credit: NASA.
Recent modeling of solar mass stars with planetary systems, found that a system with four rocky planets and four gas giants in stable orbits – and only a sparsely populated outer belt of planetesimals – has only a 15 to 25% likelihood of developing. While you might be skeptical about the validity of a model that puts our best known planetary system in the unlikely basket, there may be some truth in this finding.(…)
Read the rest of Astronomy Without A Telescope – Our Unlikely Solar System (697 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | One comment | Add to del.icio.us
Post tags: debris disks
Feed enhanced by Better Feed from Ozh
Getting ready for the world’s biggest telescope
Astronomy Magazine News Article – Released:4/4/2011
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Our Inferred Universe
A galaxy far, far away and long. long ago. UDFy-38135539 – about the most distant observed object, where UDF stands for (Hubble) Ultra-Deep Field. Credit: HST – NASA/ESA.
The universe is a big place – and getting bigger all the time – so at a large scale all unbound structures are all moving away from each other. So when we look out at distant objects, we need to remind ourselves that not only are we seeing them as they appeared in the past, when the light that hits our eyes first left them, but also that they are no longer in that location where they appear to be.(…)
Read the rest of Astronomy Without A Telescope – Our Inferred Universe (641 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us
Post tags: comoving distance
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Dark Statistics
The dark flow hypothesis. A region of the observable universe is being influenced by a mysterious something outside the observable universe (which we can’t observe). Source: universe-review.ca
The hypothetical dark flow seen in the movement of galaxy clusters requires that we can reliably identify a clear statistical correlation in the motion of distant objects which are, in any case, flowing outwards with the expansion of the universe and may also have their own individual (or peculiar) motion arising from gravitational interactions. (…)
Read the rest of Astronomy Without A Telescope – Dark Statistics (680 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us
Post tags: dark flow
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Doubly Special Relativity
The Large Hadron Collider – destined to deliver fabulous science data, but it remains uncertain if these will include an evidence basis for quantum gravity theories. Credit: CERN.
General relativity, Einstein’s theory of gravity, gives us a useful basis for mathematically modeling the large scale universe – while quantum theory gives us a useful basis for modeling sub-atomic particle physics and the likely small-scale, high-energy-density physics of the early universe – nanoseconds after the Big Bang – which general relativity just models as a singularity and has nothing else to say on the matter.
Quantum gravity theories may have more to say. By extending general relativity into a quantized structure for space-time, maybe we can bridge the gap between small and large scale physics. For example, there’s doubly special relativity. (…)
Read the rest of Astronomy Without A Telescope – Doubly Special Relativity (672 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | 7 comments | Add to del.icio.us
Post tags: quantum gravity
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Black Hole Entropy
Black holes – throw something in them and that’s the end of the story, right? Well, apparently some physicists just can’t seem to leave it there.
An easy way to think about the entropy of black holes is to consider that entropy represents the loss of free energy – that is, energy that is available to do work – from a system. Needless to say, anything you throw into a black hole is no longer available to do any work in the wider universe.(…)
Read the rest of Astronomy Without A Telescope – Black Hole Entropy (749 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us
Post tags: entropy
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Unreasonable Effectiveness
Some indication of the complex math involved in modeling a close massive binary system of compact objects – be they neutron stars or black holes. Surely, you couldn’t possibly just guess the outcome here – at least you wouldn’t think that you possibly could. Credit: NASA.
Gravitational waves are apparently devilishly difficult things to model with Einstein field equations, since they are highly dynamic and non-symmetric. Traditionally, the only way to get close to predicting the likely effects of gravity waves was to estimate the Einstein equation parameters by assuming the objects causing the gravity waves do not generate strong gravity fields themselves – and nor do they move at velocities anywhere close to the speed of light.
Trouble is, the mostly likely candidate objects that might generate detectable gravity waves – close binary neutron stars and merging black holes – have exactly those properties. They are highly compact, very massive bodies that often move at relativistic (i.e. close to the speed of light) velocities. (…)
Read the rest of Astronomy Without A Telescope – Unreasonable Effectiveness (429 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us
Post tags: General Relativity
Feed enhanced by Better Feed from Ozh
Sky & Telescope editor emeritus Leif J. Robinson passes away at age 71
Astronomy Magazine News Article – Released:3/1/2011
Astronomy.com News – Presented by Astronomy Magazine
Sky & Telescope Magazine Editor Emeritus, Leif J. Robinson, Passes Away,
Leif J. Robinson courtesy of Sky & Telescope / Dennis di Cicco
For those of us who have dreamed over the stars for years while reading Sky & Telescope magazine, we respectfully remember Leif J. Robinson, who served for 20 years as Editor in Chief. He passed away Sunday at the age of 71 at his home in Costa Rica. (…)
Read the rest of Sky & Telescope Magazine Editor Emeritus, Leif J. Robinson, Passes Away, (533 words)
© tammy for Universe Today, 2011. | Permalink | One comment | Add to del.icio.us
Post tags:
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Knots In Space
A rare double Einstein ring (SDSSJ0946+1006). Either two distant galaxies are lined up directly behind a closer massive galactic cluster (which is gravitationally-lensing their light into a double ring) – or of course it could be a donut-shaped portal to an alternate universe. You decide. Credit: NASA/ESA HST.
So finally you possess that most valuable of commodities, a traversable wormhole – and somehow or other you grab one end of it and accelerate it to a very rapid velocity. (…)
Read the rest of Astronomy Without A Telescope – Knots In Space (699 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | 12 comments | Add to del.icio.us
Post tags: wormholes
Feed enhanced by Better Feed from Ozh
New Record: Telescope Finds 19 Near-Earth Asteroids in One Night
Richard Wainscoat (left) and Marco Micheli study one of the near-Earth asteroids found on January 29. The asteroid is the roundish dot near Wainscoat’s finger. Photo by Karen Teramura
From a University of Hawaii Institute for Astronomy press release:
The Pan-STARRS PS1 telescope on Haleakala, Maui, discovered 19 near-Earth asteroids on the night of January 29, the most asteroids discovered by one telescope on a single night.
“This record number of discoveries shows that PS1 is the world’s most powerful telescope for this kind of study,” said Nick Kaiser, head of the Pan-STARRS project. “NASA and the U.S. Air Force Research Laboratory’s support of this project illustrates how seriously they are taking the threat from near-Earth asteroids.”
(…)
Read the rest of New Record: Telescope Finds 19 Near-Earth Asteroids in One Night (320 words)
© nancy for Universe Today, 2011. | Permalink | One comment | Add to del.icio.us
Post tags: Asteroids, Observatories, Pan-STARRS
Feed enhanced by Better Feed from Ozh
PS1 telescope establishes near-Earth asteroid discovery record
Astronomy Magazine News Article – Released:2/25/2011
Astronomy.com News – Presented by Astronomy Magazine
Choosing a New Telescope – GoTo or not GoTo
I am often asked by people “I’m a beginner, so what telescope should I buy?” Or more often, what GoTo telescope would I recommend for someone starting out in astronomy?
When venturing out and buying your first telescope, there are a number of factors to consider, but because of glossy advertising and our current digital age, the first telescope that people think of is a GoTo.
Do you really need a GoTo or would a manual telescope suffice? In order to make a good decision on what telescope to buy, you need to decide on what you want to use the telescope for — observing, photography, or both and does it need to be portable or not? This will help you make the best decision for the mount of your telescope.
(…)
Read the rest of Choosing a New Telescope – GoTo or not GoTo (556 words)
© Adrian West for Universe Today, 2011. | Permalink | 19 comments | Add to del.icio.us
Post tags: astrophotography, Observing, telescope reviews
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Plausibility Check
OK, this looks nice – but let’s think it through. You’ve got two binary stars with angular diameters and spectral properties roughly analogous to our Sun – shining through an atmosphere containing semi-precipitous water vapor (also known as clouds). Plausible? Credit: NASA.
So we all know the story. Uncle Owen has just emotionally blackmailed you into putting off your application to the academy for another year – and even after you just got those two new droids, darn it. So you stare mournfully at the setting binary suns and…
Hang on, they look a lot like G type stars – and if so, their roughly 0.5 degree angular diameters in the sky suggest they are both only around 1 astronomical unit away. I mean OK, you could plausibly have a close red dwarf and a distant blue giant having identical apparent diameters, but surely they would look substantially different, both in color and brightness. (…)
Read the rest of Astronomy Without A Telescope – Plausibility Check (701 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us
Post tags: binary stars
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Situation Cloudy
The Magellanic Stream trails behind the Large and Small Magellanic Clouds – two bright shapes visible below the Milky Way’s galactic disk, to the right. The stuff ahead of the Clouds is called the Leading Arm. The pink is false color – the Stream and Arm are only visible in radio wavelengths. Credit: Nidever et al.
Most people agree that the Magellanic Clouds are in orbit around the Milky Way. What’s not clear is whether it is a bound orbit or just a temporary ‘ships passing in the night’ arrangement. Something which could clarify the relationship is the Magellanic Stream, a 600,000 light year long string of gas dragged through and beyond the Small and Large Magellanic Clouds. (…)
Read the rest of Astronomy Without A Telescope – Situation Cloudy (700 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | 5 comments | Add to del.icio.us
Post tags: magellanic clouds, Magellanic Stream
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Gravity Probe B
Gravity Probe B – testing the null hypothesis that the spin axis of a gyroscope will stay aligned with a distant reference point when it’s in a free fall orbit. General relativity says it won’t.
There’s a line out of an early episode of The Big Bang Theory series, where Gravity Probe B is described as having seen ‘glimpses’ of Einstein’s predicted frame-dragging effect. In reality, it is not entirely clear that the experiment was able to definitively distinguish a frame-dragging effect from a background noise created by some exceedingly minor aberrations in its detection system.
Whether or not this counts as a glimpse – frame-dragging (the alleged last untested prediction of general relativity) and Gravity Probe B have become linked in the public consciousness. So here’s a quick primer on what Gravity Probe B may or may not have glimpsed.(…)
Read the rest of Astronomy Without A Telescope – Gravity Probe B (703 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us
Post tags: Frame-shifting
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Time Freeze
Is it ever possible to find yourself in a situation where you see the hands of a clock freeze? Nnnnnnnnnn….
There is a story told about traveling at the speed of light in which you are asked to imagine that you begin by standing in front of a big clock – like Big Ben. You realize that your current perception of time is being informed by light reflected off the face of the clock – which is telling you it’s 12:00. So if you then shoot away at the same speed as that light – all you will continue to see is that clock fixed at 12:00, since you are moving at the same speed that this information is moving. And so you discover that at the speed of light, time essentially stands still.
While there are a number of things wrong with this story – as it happens, one correct thing is that if you were able to travel at the speed of light you would experience no passage of time – although there are several reasons why this is probably an impossible situation to find yourself in.(…)
Read the rest of Astronomy Without A Telescope – Time Freeze (578 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | 12 comments | Add to del.icio.us
Post tags: time dilation
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Why Carbon?
Although we consider life on Earth to be carbon-based, the ATGC coding components of DNA are nucleotides – with a carbon content of zero. Credit: NASA (adapted image).
Last week’s AWAT Why Water? took the approach of acknowledging that while numerous solvents are available to support alien biochemistries, water is very likely to be the most common biological solvent out there – just on the basis of its sheer abundance. It also has useful chemical features that would be advantageous to alien biochemistries – particularly where its liquid phase occurs in a warmer temperature zone than any other solvent. (…)
Read the rest of Astronomy Without A Telescope – Why Carbon? (537 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | No comment | Add to del.icio.us
Post tags: carbon-based life
Feed enhanced by Better Feed from Ozh
Fermi’s Large Area Telescope sees surprising flares in Crab Nebula
Astronomy Magazine News Article – Released:1/10/2011
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Why Water?
Mono Lake – no alien biochemistry here, but makes for a nice photo all the same. Credit: NASA.
The assumption that alien biochemistries probably require liquid water may seem a little Earth-centric. But given the chemical possibilities available from the most abundant elements in the universe, even an alien scientist with a different biochemistry would probably agree that a water-solvent-based biochemistry is quite likely to occur elsewhere in the universe – and might well be the most likely foundation for a complex ecosystem in which intelligent life could develop.(…)
Read the rest of Astronomy Without A Telescope – Why Water? (708 words)
© Steve Nerlich for Universe Today, 2011. | Permalink | 5 comments | Add to del.icio.us
Post tags: alternative biochemistries
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Secular Evolution
M51 – the Whirlpool Galaxy. Like most spiral galaxies, the spiral arms are really density waves. Drag forces produced by these density waves could drive the ‘secular’ evolution of galaxies. Credit: NASA-HST.
A traditional galaxy evolution model has it that you start with spiral galaxies – which might grow in size through digesting smaller dwarf galaxies – but otherwise retain their spiral form relatively undisturbed. It is only when these galaxies collide with another of similar size that you first get an irregular ‘train-wreck’ form, which eventually settles into a featureless elliptical form – full of stars following random orbital paths rather than moving in the same narrow orbital plane that we see in the flattened galactic disk of a spiral galaxy.
The concept of secular galaxy evolution challenges this notion – where ‘secular’ means separate or isolated. Theories of secular evolution propose that galaxies naturally evolve along the Hubble sequence (from spiral to elliptical), without merging or collisions necessarily driving changes in their form. (…)
Read the rest of Astronomy Without A Telescope – Secular Evolution (499 words)
© Steve Nerlich for Universe Today, 2010. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: density waves, galaxy formation
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – The Edge of Greatness
The foamy-looking cosmic web – at this scale we run out of superlatives to describe the large scale structure of the universe. Credit: NASA.
The so-called End of Greatness is where you give up trying to find more superlatives to describe large scale objects in the universe. Currently the Sloan Great Wall – a roughly organised collection of galactic superclusters partitioning one great void from another great void – is about where most cosmologists draw the line.
Beyond the End of Greatness, it’s best just to consider the universe as a holistic entity – and at this scale we consider it isotropic and homogenous, which we need to do to make our current cosmology math work. But at the very edge of greatness, we find the cosmic web. (…)
Read the rest of Astronomy Without A Telescope – The Edge of Greatness (526 words)
© Steve Nerlich for Universe Today, 2010. |
Permalink |
No comment |
Add to
del.icio.us
Post tags: cosmic web, topology
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Forbidden Planets
The theorized evolution of the circumbinary planet PSR B1620-26 b. Credit: NASA.
Binary star systems can have planets – although these are generally assumed to be circumbinary (where the orbit encircles both stars). As well as the fictional examples of Tatooine and Gallifrey, there are real examples of PSR B1620-26 b and HW Virginis b and c – thought to be cool gas giants with several times the mass of Jupiter, orbiting several astronomical units out from their binary suns.
Planets in circumstellar orbits around a single star within a binary system are traditionally considered to be unlikely due to the mathematical implausibility of maintaining a stable orbit through the ‘forbidden’ zones – which result from gravitational resonances generated by the motion of the binary stars. The orbital dynamics involved should either fling a planet out of the system or send it crashing to its doom into one or other of the stars. However, there may be a number of windows of opportunity available for ‘next generation’ planets to form at later stages in the evolving life of a binary system. (…)
Read the rest of Astronomy Without A Telescope – Forbidden Planets (523 words)
© Steve Nerlich for Universe Today, 2010. |
Permalink |
14 comments |
Add to
del.icio.us
Post tags: orbital dynamics
Feed enhanced by Better Feed from Ozh
Spitzer Space Telescope reveals first carbon-rich planet
Astronomy Magazine News Article – Released:12/9/2010
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Through A Lens Darkly
Gravitational lensing in action – faint hints of an ‘Einstein ring’ forming about light sources which have been ‘lensed’ by the warping of space-time. If the galactic cluster causing the warping was orientated in a plane that was face-on directly at Earth – the Einstein ring would be much more apparent. Credit: HST, NASA.
Massive galactic clusters – which are roughly orientated in a plane that is roughly face-on to Earth – can generate strong gravitational lensing. However, several surveys of such clusters have reached the conclusion that these clusters have a tendency towards lensing too much – at least more than is predicted based on their expected mass.
Known (to some researchers working in the area) as the ‘over-concentration problem’, it does seem to be a prima facie case of missing mass. But rather than just playing the dark matter card, researchers are pursuing more detailed observations – if only to eliminate other possible causes. (…)
Read the rest of Astronomy Without A Telescope – Through A Lens Darkly (593 words)
© Steve Nerlich for Universe Today, 2010. | Permalink | No comment | Add to del.icio.us
Post tags: The Sunyaev-Zel’dovich effect
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Black Hole Evolution
The idea that every galaxy of significant size has a supermassive black hole at its centre keeps gaining momentum. So… coincidence? Or are these SMBHs somehow fundamental to the process of galaxy formation? Credit: NASA.
While only observable by inference, the existence of supermassive black holes (SMBHs) at the centre of most – if not all – galaxies remains a compelling theory supported by a range of indirect observational methods. Within these data sources, there exists a strong correlation between the mass of the galactic bulge of a galaxy and the mass of its central SMBH – meaning that smaller galaxies have smaller SMBHs and bigger galaxies have bigger SMBHs.
Linked to this finding is the notion that SMBHs may play an intrinsic role in galaxy formation and evolution – and might have even been the first step in the formation of the earliest galaxies in the universe, including the proto-Milky Way.
(…)
Read the rest of Astronomy Without A Telescope – Black Hole Evolution (669 words)
© Steve Nerlich for Universe Today, 2010. | Permalink | 11 comments | Add to del.icio.us
Post tags: galaxy formation, supermassive black holes
Feed enhanced by Better Feed from Ozh
Mission to asteroid gets help from Hubble Space Telescope
Astronomy Magazine News Article – Released:10/11/2010
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Necropanspermia
Could an alien spore really travel light years between different star systems? Well, as long as your theory doesn’t require it to be alive when it arrives – sure it can.
The idea that a tiny organism could hitchhike aboard a mote of space dust to cross vast stretches of space and time until it landed and took up residence on the early Earth does seem a bit implausible. More likely any such organisms would have been long dead by the time they reached Earth. But… might those long dead alien carcasses still have provided the genomic template that kick started life on Earth? Welcome to necropanspermia.
(…)
Read the rest of Astronomy Without A Telescope – Necropanspermia (560 words)
© Steve Nerlich for Universe Today, 2010. | Permalink | 7 comments | Add to del.icio.us
Post tags: panspermia
Feed enhanced by Better Feed from Ozh
The Fermi telescope discovers giant structure in our galaxy
Astronomy Magazine News Article – Released:11/10/2010
Astronomy.com News – Presented by Astronomy Magazine
Costs for James Webb Telescope Soar — Again
Artists concept of the James Webb Space Telescope in space. Credit: NASA
The price tag for NASA’s next big space telescope keeps rising and the launch date will likely be delayed as well. A new report from an independent panel on the James Webb Space Telescope reveals it will take about $ 6.5 billion to launch and run the telescope for its projected 10-year mission. The price had previously ballooned from $ 3.5 billion to $ 5 billion. Originally the telescope was slated to launch in 2007, but was pushed back to 2014. Now, the panel says, the earliest launch date would be in September 2015.
(…)
Read the rest of Costs for James Webb Telescope Soar — Again (614 words)
© nancy for Universe Today, 2010. | Permalink | 6 comments | Add to del.icio.us
Post tags: NASA James Webb Space Telescope
Feed enhanced by Better Feed from Ozh
Fermi Telescope Finds Giant Structure in the Milky Way
From end to end, the newly discovered gamma-ray bubbles extend 50,000 light-years, or roughly half of the Milky Way’s diameter, as shown in this illustration. Credit: NASA
From a NASA press release:
NASA’s Fermi Gamma-ray Space Telescope has unveiled a previously unseen structure centered in the Milky Way. The feature spans 50,000 light-years and may be the remnant of an eruption from a supersized black hole at the center of our galaxy.
“What we see are two gamma-ray-emitting bubbles that extend 25,000 light-years north and south of the galactic center,” said Doug Finkbeiner, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., who first recognized the feature. “We don’t fully understand their nature or origin.”
(…)
Read the rest of Fermi Telescope Finds Giant Structure in the Milky Way (577 words)
© nancy for Universe Today, 2010. | Permalink | 2 comments | Add to del.icio.us
Post tags: Fermi Telescope, milky way
Feed enhanced by Better Feed from Ozh
Astronomy Without A Telescope – Indigenous Australian Astronomy
The Homunculus Nebula arising from the Eta Carinae star system – thought to be stellar material blown off by this massive star system during a ‘supernova impostor’ event that occurred around 1840.
Eta Carinae is a massive binary system – of which the dominant member is an eruptive luminous blue variable star. The system’s last significant eruption – also known as the ‘great outburst’ – made Eta Carinae briefly the second brightest star system in the night sky after Sirius over the period of 1837 to 1845, after which it faded again. The great outburst left behind the Homunculus Nebula – and also left an impression on the indigenous Aboriginal people of Australia who observed it at that time.
(…)
Read the rest of Astronomy Without A Telescope – Indigenous Australian Astronomy (720 words)
© Steve Nerlich for Universe Today, 2010. | Permalink | 5 comments | Add to del.icio.us
Post tags: Archaeoastronomy
Feed enhanced by Better Feed from Ozh
Spitzer telescope finds that space buckyballs thrive
Astronomy Magazine News Article – Released:10/28/2010
Astronomy.com News – Presented by Astronomy Magazine
Astronomy Without A Telescope – Warp Drive On Paper
It’s sixteen years since Miguel Alcubierre suggested that faster-than-light travel might be achieved by generating a warp bubble that contracts space-time ahead of the spaceship and expands it behind. Now a metamaterial test laboratory is available to see if this idea really could work. Image sourced from: andersoninstitute.com
The Alcubierre drive is one of the better known warp drive on paper models – where a possible method of warp drive seems to work mathematically as long as you don’t get too hung up on real world physics and some pesky boundary issues.
Recently the Alcubierre drive concept has been tested within mathematically modeled metamaterial – which can provide a rough analogy of space-time. Interestingly, in turns out that under these conditions the Alcubierre drive is unable to break the light barrier – but quite capable of doing 25% of light speed, which is not what you would call slow.
(…)
Read the rest of Astronomy Without A Telescope – Warp Drive On Paper (620 words)
© Steve Nerlich for Universe Today, 2010. | Permalink | 9 comments | Add to del.icio.us
Post tags: Alcubierre metric, metamaterial
Feed enhanced by Better Feed from Ozh