Tag: astronomy
Hubble Makes its One Millionth Science Observation
More delays for the James Webb Space Telescope?
More delays for the James Webb Space Telescope?
More delays for the James Webb Space Telescope?
Mysterious Light Burst Captured by Hawaii Telescope
Mysterious bubble of light, caused by military suborbital rocket, captured by Hawaii telescopes.
Mysterious bubble of light, caused by military suborbital rocket, captured by Hawaii telescopes.
The most distant quasar ever found
Astronomers have found the most distant quasar ever, and are baffled by its existence.
The light from the quasar started its journey toward us when the universe was only 6% of its present age, a mere 770 million years after the Big Bang, at a redshift of about 7.1 [3]. “This gives astronomers a headache,” says lead author Daniel Mortlock, from Imperial College London. “It’s difficult to understand how a black hole a billion times more massive than the Sun can have grown so early in the history of the universe. It’s like rolling a snowball down the hill and suddenly you find that it’s 20 feet across!”
Astronomers have found the most distant quasar ever, and are baffled by its existence.
The light from the quasar started its journey toward us when the universe was only 6% of its present age, a mere 770 million years after the Big Bang, at a redshift of about 7.1 [3]. “This gives astronomers a headache,” says lead author Daniel Mortlock, from Imperial College London. “It’s difficult to understand how a black hole a billion times more massive than the Sun can have grown so early in the history of the universe. It’s like rolling a snowball down the hill and suddenly you find that it’s 20 feet across!”
The faces of Vesta
Want to send a probe to another planet? Cut costs!
Want to send a probe to another planet? Do it cheaply, as these scientists did.
Want to send a probe to another planet? Do it cheaply, as these scientists did.
Cassini directly samples the plumes from Enceladus and finds an ocean-like Spray
Cassini has directly sampled the plumes from Enceladus and discovered a salty ocean-like spray.
The new paper analyzes three Enceladus flybys in 2008 and 2009 with the same instrument, focusing on the composition of freshly ejected plume grains. The icy particles hit the detector target at speeds between 15,000 and 39,000 mph (23,000 and 63,000 kilometers per hour), vaporizing instantly. Electrical fields inside the cosmic dust analyzer separated the various constituents of the impact cloud.
The data suggest a layer of water between the moon’s rocky core and its icy mantle, possibly as deep as about 50 miles (80 kilometers) beneath the surface. As this water washes against the rocks, it dissolves salt compounds and rises through fractures in the overlying ice to form reserves nearer the surface. If the outermost layer cracks open, the decrease in pressure from these reserves to space causes a plume to shoot out. Roughly 400 pounds (200 kilograms) of water vapor is lost every second in the plumes, with smaller amounts being lost as ice grains. The team calculates the water reserves must have large evaporating surfaces, or they would freeze easily and stop the plumes.
Cassini has directly sampled the plumes from Enceladus and discovered a salty ocean-like spray.
The new paper analyzes three Enceladus flybys in 2008 and 2009 with the same instrument, focusing on the composition of freshly ejected plume grains. The icy particles hit the detector target at speeds between 15,000 and 39,000 mph (23,000 and 63,000 kilometers per hour), vaporizing instantly. Electrical fields inside the cosmic dust analyzer separated the various constituents of the impact cloud.
The data suggest a layer of water between the moon’s rocky core and its icy mantle, possibly as deep as about 50 miles (80 kilometers) beneath the surface. As this water washes against the rocks, it dissolves salt compounds and rises through fractures in the overlying ice to form reserves nearer the surface. If the outermost layer cracks open, the decrease in pressure from these reserves to space causes a plume to shoot out. Roughly 400 pounds (200 kilograms) of water vapor is lost every second in the plumes, with smaller amounts being lost as ice grains. The team calculates the water reserves must have large evaporating surfaces, or they would freeze easily and stop the plumes.
Help pick the Kuiper Belt targets of New Horizons after it flies past Pluto
Citizen astronomers: Help pick the Kuiper Belt targets that New Horizons will visit after it flies past Pluto.
Citizen astronomers: Help pick the Kuiper Belt targets that New Horizons will visit after it flies past Pluto.
Hadrian built his country estate with the buildings aligned with the sun
The Roman emperor Hadrian built his country estate with the buildings aligned with the sun.
For centuries, scholars have thought that the more than 30 buildings at Hadrian’s palatial country estate were oriented more or less randomly. But De Franceschini says that during the summer solstice, blades of light pierce two of the villa’s buildings.
In one, the Roccabruna, light from the summer solstice enters through a wedge-shaped slot above the door and illuminates a niche on the opposite side of the interior (see image). And in a temple of the Accademia building, De Franceschini has found that sunlight passes through a series of doors during both the winter and summer solstices.
The Roman emperor Hadrian built his country estate with the buildings aligned with the sun.
For centuries, scholars have thought that the more than 30 buildings at Hadrian’s palatial country estate were oriented more or less randomly. But De Franceschini says that during the summer solstice, blades of light pierce two of the villa’s buildings.
In one, the Roccabruna, light from the summer solstice enters through a wedge-shaped slot above the door and illuminates a niche on the opposite side of the interior (see image). And in a temple of the Accademia building, De Franceschini has found that sunlight passes through a series of doors during both the winter and summer solstices.
The Pan-STARRS Telescope has found comet that might provide a show in 2013
The Pan-STARRS Telescope has found a comet that might provide us all a show in 2013.
The Pan-STARRS Telescope has found a comet that might provide us all a show in 2013.
An X-ray deep field over six weeks by Chandra finds massive black holes common in early universe
An X-ray deep field image taken over a six week period by Chandra had found that massive black holes are common in early universe.
These results imply that between 30% and 100% of the distant galaxies contain growing supermassive black holes. Extrapolating these results from the relatively small field of view that was observed to the full sky, there are at least 30 million supermassive black holes in the early Universe. This is a factor of 10,000 larger than the estimated number of quasars in the early Universe.
An X-ray deep field image taken over a six week period by Chandra had found that massive black holes are common in early universe.
These results imply that between 30% and 100% of the distant galaxies contain growing supermassive black holes. Extrapolating these results from the relatively small field of view that was observed to the full sky, there are at least 30 million supermassive black holes in the early Universe. This is a factor of 10,000 larger than the estimated number of quasars in the early Universe.
The progenitor of the May supernova in M51 identified
The progenitor star that produced the May supernovae in the Whirlpool Galaxy (also known as M51) has been identified, and it isn’t what scientists predicted.
In a preprint paper published today on the Los Alamos astro-ph website, astronomers describe the star that exploded as a yellow supergiant, not a red supergiant or Wolf-Rayet star, as predicted by the theory explaining this particular type of supernova. Moreover, though theory also favors the star being a member of a binary system, the progenitor of 2011dh appears to be a lone star, not even a member of a cluster.
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Europe Downscales Monster Telescope to Save Money
Europe has decided to shrink the design of the gigantic Extremely Large Telescope (yes, that’s really its name) by 13% to save money.
Europe has decided to shrink the design of the gigantic Extremely Large Telescope (yes, that’s really its name) by 13% to save money.
A galaxy with two central supermassive black holes
A galaxy with two central supermassive black holes.
A galaxy with two central supermassive black holes.
Magnetic bubbles at the edge of the solar system
Magnetic bubbles at the edge of the solar system.
Magnetic bubbles at the edge of the solar system.
A press conference of my very own
This week the Space Telescope Science Institute in Baltimore, Maryland was holding a conference on the future research possibilities of the James Webb Space Telescope, and ended the conference with a writer’s workshop/press conference today.
Not surprisingly, there was not a lot of press interest. The Webb telescope is way behind schedule and over budget, and is not scheduled for launch until 2018. For most of the press, a press conference now on what Webb might someday do is really nothing more than a NASA sales pitch. Most reporters, including myself, don’t find these kinds of press conferences of much worth.
However, after thinking about it a bit, I decided to go, with the hope that I might be able to find out some more details about the state of the telescope’s construction.
To my astonishment, I discovered how little press interest there was, as it turned out I was the only journalist there! When the presentations ended, the whole workshop became an exercise in answering Bob Zimmerman’s questions about Webb and astronomy. I felt a bit embarrassed about this, but then decided the only stupid question is the one you don’t ask, and forged ahead. Moreover, the situation probably was far more embarrassing for the press people at the Institute then it was for me.
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The remnant of supernova 1987a Lights Up
The remnant of supernova 1987a lights up.
This supernova is the only naked eye supernova since the invention of the telescope, and has been tracked by Hubble for two decades.
The remnant of supernova 1987a lights up.
This supernova is the only naked eye supernova since the invention of the telescope, and has been tracked by Hubble for two decades.
When galaxies collide
An evening pause: a beautiful simulation of galaxy collision. Hat tip: Sky and Telescope.
Supernova flares in M51
A new supernova has erupted in the nearby galaxy M51, 23 million light years away.
A new supernova has erupted in the nearby galaxy M51, 23 million light years away.
Webb telescope disaster destroys NASA astrophysics budget
The James Webb Space Telescope: The disaster that destroyed NASA’s astrophysics program.
The James Webb Space Telescope: The disaster that destroyed NASA’s astrophysics program.
Dancing Telescopes
Planetary scientists push for Enceladus mission to search for alien life
Planetary scientists push for Enceladus mission to search for alien life.
Planetary scientists push for Enceladus mission to search for alien life.
Astronomical Deficit Forces Downsizing of U.S. Telescope Projects
Budget deficits signal a decline in spending for astronomy telescopes, both on the ground and in space, for the next decade.
Budget deficits signal a decline in spending for astronomy telescopes, both on the ground and in space, for the next decade.
The most distant explosion ever seen
The Spitzer photo atlas of galactic “train wrecks”
A photo atlas of galactic “train wrecks.”
A photo atlas of galactic “train wrecks.”
More on the new Kepler results: Lots of multiple planet systems
More on the new Kepler results: Lots of multiple planet systems.
More on the new Kepler results: Lots of multiple planet systems.
New results from Kepler
New results from Kepler.
New results from Kepler.
Want to go to an asteroid?
A paper published today on the Los Alamos astro-ph preprint website has taken a close look at identifying the best nearby asteroids ideal for mounting a manned mission. The conclusion: our survey of such asteroids is very incomplete (only 65 known), and due to their location in Earthlike orbits they are very difficult to study.
Ultra-low delta-v NEOs are not readily found. Their closely Earth-like orbits mean that most of the time they are in the daytime sky, as seen from the Earth, and so are effectively undetectable. As they approach within <1AU of the Earth they start to lie near quadrature, and so come into the dawn or dusk sky on Earth. The strong scattered sunlight background makes optical surveys toward the dawn or dusk much less sensitive and, in practice, surveys do not look in these directions, preferring to observe where the sky is dark, within 45 degrees, and at most 60 degrees, of the anti-Sun, opposition, direction. As a consequence the lowest delta-v NEOs are undercounted by current surveys, and the factor by which they are undercounted is not yet known.
The paper proposes building a dedicated unmanned infrared mission and placing it in a Venus-like orbit where it would be better placed to see these difficult but important objects.