CfA: Pan-STARRS Now Fully Operational

[bystander]

Pan-STARRS Asteroid Hunter and Sky Surveyor Now Fully Operational
Harvard-Smithsonian Center for Astrophysics (2010-08) | 16 June 2010

Astronomers announced today that the first Pan-STARRS (Panoramic Survey Telescope & Rapid Response System) telescope, PS1, is fully operational. This innovative facility will be at the front line of Earth defense by searching for "killer" asteroids and comets. It will map large portions of the sky nightly, making it an efficient sleuth for not just asteroids but also supernovae and other variable objects.
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Pan-STARRS will map one-sixth of the sky every month. By casting a wide net, it is expected to catch many moving objects within our solar system. Frequent follow-up observations will allow astronomers to track those objects and calculate their orbits, identifying any potential threats to Earth. PS1 also will spot many small, faint bodies in the outer solar system that hid from previous surveys.
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Pan-STARRS features the world's largest digital camera -- a 1,400-megapixel (1.4 gigapixel) monster. With it, astronomers can photograph an area of the sky as large as 36 full moons in a single exposure. In comparison, a picture from the Hubble Space Telescope's WFC3 camera spans an area only one-hundredth the size of the full moon (albeit at very high resolution).
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Located atop the dormant volcano Haleakala, Pan-STARRS exploits the unique combination of superb observing sites and technical and scientific expertise available in Hawaii. Funding for the development of the observing system was provided by the U.S. Air Force.

[bystander]

Pan-STARRS 1 Telescope Begins Science Mission
Institute for Astronomy | University of Hawaii | 16 June 2010

The world became a slightly safer place on May 13, when the Pan-STARRS 1 (PS1) telescope in Hawaii started surveying the sky for killer asteroids.

This 1.8 meter (60-inch) diameter telescope on Haleakala is designed to automatically search the skies for objects that either move or change their brightness from night to night. It contains the world’s largest digital camera, with 1,400 megapixels.

“Although modest in size, this telescope is on the cutting edge of technology,” said Dr. Nick Kaiser, head of the Pan-STARRS project. “It can image a patch of sky about 40 times the area of the full moon, much larger than any similar-sized telescope on Earth or in space.”

Designed and built by astronomers and engineers of the Pan-STARRS project at the University of Hawaii at Manoa, PS1 has now been turned over to the PS1 Science Consortium, a group of ten institutions, including UH Manoa, in the United States, Germany, United Kingdom and Taiwan that are funding the PS1 Science Mission.

The giant digital camera will take over 500 exposures each night and send about four terabytes of data (equivalent to what 1,000 DVDs can hold) to the Maui High Performance Computing Center for analysis. Computers will rapidly compare each exposure with corresponding ones taken either a few minutes or a few days earlier to find objects that have moved or whose brightness has changed.

In the next three years, PS1 is expected to discover about 100,000 asteroids and to determine if any of them are on a collision course with Earth. It will catalog five billion stars and 500 million galaxies.

PS1 will also be used to compile the most comprehensive digital map of the 75 percent of the universe visible from Hawaii.

UH astronomers will use the data to search for killer asteroids, to find brown dwarfs and distant quasars, to watch supernova explosions in distant galaxies and to test their latest theories concerning dark matter and dark energy.

PS1 is the experimental prototype for the larger PS4 telescope, which will have four times the power of PS1 and is planned for Mauna Kea.

[bystander]

Astronomers' first "movie of the sky": Pan-STARRS survey starts science mission
Max Plank Institute for Astronomy | 16 June 2010

The Pan-STARRS project has begun a unique program of observing three quarters of the night sky: the systematic search for astronomical objects that change over time. Its data will enable astronomers to search for dangerous asteroids on a possible collision course with Earth, but also to tackle some of astronomy's deepest mysteries: Dark Matter and Dark Energy. Scientists of the Max Planck Institutes for Astronomy and for Extraterrestrial Physics are involved in a number of the survey's key projects, including searches for extra-solar planets, for "failed stars" known as Brown Dwarfs, and for distant active galaxies.

The timeless configuration of stars in the night sky is a veritable symbol of changelessness. Yet closer inspection reveals that there is action in the sky – from objects such as variable stars to rare events such as stellar explosions which are visible for a brief period of time only. A new survey specifically targets such celestial change: Pan-STARRS1 will make repeated observations that should cover all regions within 75% of the night sky at least 30 times, while regions of special interest will be observed several hundred times. The result is a unique "movie of the sky".

"Every month, Pan-STARRS1 will observe one sixth of the sky at five different wavelengths" explains Dr. Roberto Saglia of the Max Planck Institute for Extraterrestrial Physics. "In this way, we can track changes in brightness. We can also use our data for an especially deep look into certain regions of the sky." These regions are observed every night. The resulting data will also be used to draw a particularly detailed three-dimensional map of the Milky Way Galaxy, our cosmic home, and to produce a complete inventory of variable astronomical objects for our cosmic neighbour, the Andromeda galaxy.

Pan-STARRS1 also acts as a classical survey, where astronomers look for known types of celestial objects. It will search, among other things, for extremely faint and red objects, such as Brown Dwarfs (objects that do not have sufficient mass to evolve into proper stars) and the earliest active galaxies (quasars at redshift z = 7) at distances of more than 13 billion light-years. Another part of the search has a very practical goal: Pan-STARRS1 is set to chart asteroids that could potentially collide with Earth in a catastrophic "global impact" event.

Pan-STARRS' repeated observations of large regions of the sky make it the ideal tool to track phenomena that change over time. A key example are "transiting exoplanets" – planets around distant stars that, as seen from Earth, periodically move in front of their mother star, obscuring a tiny fraction of the star's light and thus causing a slight dip in its apparent brightness. Its observational strategy also increases the chances of Pan-STARRS1 to observe very rare, ephemeral phenomena. An example: With luck, the survey could catch a distant galaxy's central black hole in the act of swallowing a star – an event that leads to an increase in brightness that lasts only a few days. In addition, Pan-STARRS1 astronomers brace for the unexpected. "Whenever astronomers have tried out a new way of looking at the sky, they've been in for surprises," says Prof. Dr. Hans-Walter Rix of the Max Planck Institute for Astronomy. "Pan-STARRS1 is the first systematic, large-scale survey of time-dependent phenomena in the night sky. If history is any guide, we are bound to find something completely new."

The Pan-STARRS1 observatory on Haleakala, Maui, just before sunrise. Credit: Rob Ratowski

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The galaxy M51 and its companion NGC 5195 as seen by Pan-STARRS1. In full resolution, each pixel represents native resolution of 0.26 arcsec. Credit: Pan-STARRS, Institute for Astronomy, University of Hawaii

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[bystander]

UK scientists focus on revealing hidden mysteries of the Universe
Durham University | 17 June 2010

Secrets of the Universe are to be revealed by a new telescope equipped with the world's most powerful digital camera.

The Pan-STARRS sky survey telescope - known as PS1 - will enable scientists to better understand the mysteries of dark matter and dark energy, the material that is thought to account for much of the mass of the universe but has never been proven to exist.

Astronomers from the Universities of Durham, Edinburgh and Queen's University Belfast together with researchers from around the world are using the telescope to scan the skies from dusk to dawn each night.
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Scientists believe the device, which was built by the University of Hawaii, will provide vital clues into the nature of dark energy and dark matter. They hope to use images of galaxies to validate Einstein's theory of general relativity, which predicts that light can bend around an object in space - such as dark matter - because it is pulled towards the object by gravity.

[bystander]

Asteroid hunters part-blinded by the military
New Scientist | Space | 28 June 2010

THE first of the asteroid-hunting Pan-STARRS telescopes is now on the lookout for threatening near-Earth objects, but its vision is impaired due to the US military.

From its perch atop the Haleakala volcano in Maui, Hawaii, PS1's mammoth, 1400-megapixel camera should uncover 100,000 new asteroids and identify any that are on a collision course with Earth. However, the US air force, which funded the development of the telescope, requires that software automatically black out a swathe of pixels to hide the trajectories of passing satellites.

Last year this restriction, plus other shortcomings, meant that just 68 per cent of the total sky imaged produced usable pictures. As of March, improvements in image processing have boosted that figure to 76 per cent, says team member Eric Bell. Still, the asteroid hunters have had to add an extra set of observations for certain patches of sky to compensate for the possibility that an object might whizz by undetected.

Seems counter-intuitive to me. Wouldn't information about which swathes are being deleted tell you at least enough about the satellite trajectories that you could track them yourself? What is the USAF gaining here at the detriment of science?

[Beyond]

Wouldn't that military requirement come under the heading of "snafu" as so much of goverment does?
Why would the planet be slightly safer if a telescope did happen to catch a "killer" asteroid?? What could be done about it?

[Chris Peterson]

Why would the planet be slightly safer if a telescope did happen to catch a "killer" asteroid?? What could be done about it?

If it is an asteroid that's going to hit soon, probably nothing. But if the risk is several orbits away (as would be far more likely) there are a number of proposed options available to deflect an asteroid. Something as simple as exploding a bomb full of black or white powder across one side might be all you'd need to tweak its trajectory.

[Chris Peterson]

Seems counter-intuitive to me. Wouldn't information about which swathes are being deleted tell you at least enough about the satellite trajectories that you could track them yourself? What is the USAF gaining here at the detriment of science?

They aren't gaining much. But you are dealing with people who are paranoid by nature, and love keeping their secrets- even when they aren't secret. Most classified satellites are already being tracked by amateurs, and you can download their orbital elements from unofficial sites. In addition, other surveys will be coming on line over the next few years, and those have no military funding. You can bet their data won't have satellites blacked out. In ten years, amateurs will be able to approach home operated survey systems not that different from Pan-STARRS in capability.

[neufer]

Why would the planet be slightly safer if a telescope did happen to catch a "killer" asteroid?? What could be done about it?

If it is an asteroid that's going to hit soon, probably nothing. But if the risk is several orbits away (as would be far more likely) there are a number of proposed options available to deflect an asteroid. Something as simple as exploding a bomb full of black or white powder across one side might be all you'd need to tweak its trajectory.

I'm somewhat more pessimistic about what can be done practically "several orbits away" (without the use of nuclear weapons).

Take 99942 Apophis:

• Orbital period 323.58 d
  Orbital speed 30.728 km/s
  Dimensions ~270 m
  Mass 27 million metric tons

A one hour change in Apophis's orbital period would require ~ 1.28 m/s change in Apophis's orbital speed.

But this would require some 16,000 metric tons of fuel for a hydrazine rocket (with exhaust velocity ~2,160 m/s) strapped unto the asteroid.

The Saturn V had a payload of only 45 metric tons to the lunar vicinity.

Thus it would take at least 500 Saturn V's simply to get sufficient hydrazine fuel to Apophis.

A 30 m asteroid might be doable but...forget an Apophis.
(We might just take our chances with a 30 m asteroid, however.)

A non-nuclear "Apophis solution" would require a lead time of many decades IMO.

[Chris Peterson]

I'm somewhat more pessimistic about what can be done practically "several orbits away" (without the use of nuclear weapons).

Of course, it depends on the length of the orbit, and on just how much the orbit needs to be changed (it's not just time, but a combination of time, inclination, eccentricity, etc). All I'm suggesting is that for objects in the several hundred meter size range, the odds are high that we would detect them with many years advance warning. Those are objects we actually have some hope of dealing with. Of course, it is easy to construct scenarios where there is nothing we can do.

[bystander]

Pan-STARRS Discovers Its First Potentially Hazardous Asteroid
Center for Astrophysics | 27 Sept 2010

2010 ST3 (Credit: PS1SC)

The Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) PS1 telescope has discovered an asteroid that will come within 4 million miles of Earth in mid-October. The object is about 150 feet in diameter and was discovered in images acquired on September 16, when it was about 20 million miles away.

It is the first "potentially hazardous object" (PHO) to be discovered by the Pan-STARRS survey and has been given the designation "2010 ST3."

"Although this particular object won't hit Earth in the immediate future, its discovery shows that Pan-STARRS is now the most sensitive system dedicated to discovering potentially dangerous asteroids," said Robert Jedicke, a University of Hawaii member of the PS1 Scientific Consortium, who is working on the asteroid data from the telescope. "This object was discovered when it was too far away to be detected by other asteroid surveys," Jedicke noted.
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Most of the largest PHOs have already been catalogued, but scientists suspect that there are many more under a mile across that have not yet been discovered. These could cause devastation on a regional scale if they ever hit our planet. Such impacts are estimated to occur once every few thousand years.
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Two images of 2010 ST3 (circled in green) taken by PS1 about 15 minutes apart on the night of September 16 show the asteroid moving against the background field of stars and galaxies. Each image is about 100 arc seconds across.

[neufer]

Pan-STARRS Discovers Its First Potentially Hazardous Asteroid
Center for Astrophysics | 27 Sept 2010

The Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) PS1 telescope has discovered an asteroid that will come within 4 million miles of Earth in mid-October. The object is about 150 feet [meters?] in diameter and was discovered in images acquired on September 16, when it was about 20 million miles away.

It is the first "potentially hazardous object" (PHO) to be discovered by the Pan-STARRS survey and has been given the designation "2010 ST3."

"Although this particular object won't hit Earth in the immediate future, its discovery shows that Pan-STARRS is now the most sensitive system dedicated to discovering potentially dangerous asteroids," said Robert Jedicke, a University of Hawaii member of the PS1 Scientific Consortium, who is working on the asteroid data from the telescope. "This object was discovered when it was too far away to be detected by other asteroid surveys," Jedicke noted.
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Most of the largest PHOs have already been catalogued, but scientists suspect that there are many more under a mile across that have not yet been discovered. These could cause devastation on a regional scale if they ever hit our planet. Such impacts are estimated to occur once every few thousand years.

Nice find Pan-STARRS but 2010 ST3 is too small to be a potentially hazardous object (PHO):

<<A potentially hazardous object (PHO) is an asteroid (PHA) or comet (PHC) with an orbit such that it has the potential to make close approaches to the Earth and a size large enough to cause significant regional damage in the event of impact.

An object is considered a PHO if its minimum orbit intersection distance (MOID) with respect to Earth is less than 0.05 astronomical units (AU) and its diameter is AT LEAST 150 m. This is big enough to cause unprecedented regional devastation in the case of a land impact, or a major tsunami in the case of an ocean impact. Such impact events occur on average once per 10,000 years or less.

The diameter of most asteroids is not known with any accuracy. For this reason NASA and JPL use the more practical measure of absolute magnitude. Any asteroid with an absolute magnitude of 22.0 or brighter is assumed to be of the required size, although only a coarse estimation of size can be found from the object's magnitude because an assumption must be made for its albedo which is also not usually known for certain. The NASA near-Earth object program uses an assumed albedo of 0.13 for this purpose.

Near the start of October 2008, NASA had listed 982 PHAs and 65 PHCs. The total Solar System inventory continues to grow, as of 2010, 1,111 PHA are known. Searches for yet-undiscovered PHOs are ongoing, with the most prolific the year prior to June 2005 being the LINEAR and Catalina surveys. Once found, each PHO is studied by various means, including optical, infrared and radar observations, to further determine its characteristics, such as size, composition, rotation state, and to more accurately determine its orbit. Both professional and amateur astronomers participate in such monitoring. During an asteroid's close approaches to planets or moons it will be subject to gravitational perturbation, modifying its orbit, and potentially changing a previously non-threatening asteroid into a PHA or vice versa.>>

[bystander]

New Telescope Exploring Solar System "Outback"
Harvard-Smithsonian Center for Astrophysics | 2011 Jan 11

In the outer reaches of our solar system lies a mysterious region far more remote and difficult to explore than the Australian outback. It remains the only part of our solar system not visited by spacecraft. Called the Kuiper Belt, this area beyond Neptune is home to the dwarf planets Pluto, Eris, Makemake, and Haumea. It also harbors thousands of smaller objects that form a second, icy asteroid belt (or more appropriately, comet belt). In this realm of perpetual twilight, the distant sun looks like just another bright star.

A new telescope has begun to virtually explore the solar system outback, and already is scoring discoveries. The Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) PS1 telescope has found ten Kuiper Belt residents. Based on their brightnesses, the newfound objects range in size from 180 to 300 miles (300 to 500 km).

"We're excited that Pan-STARRS is beginning to find these objects," said Smithsonian astronomer Matthew Holman, who leads the Pan-STARRS-1 Outer Solar System Key Project.

"It marks the tip of the iceberg for future Pan-STARRS discoveries," he added.

Holman presented the findings in a press conference at the 217th meeting of the American Astronomical Society.

The Outer Solar System Key Project is part of a larger survey to which 60 percent of Pan-STARRS telescope time will be devoted. Over the course of the coming months and years, PS1 will repeatedly survey the full sky that is visible from its location on Haleakala, spotting objects as faint as magnitude 23 (10 million times fainter than visible to the unaided eye). "The survey is expected to find a whole range of objects from small, nearby asteroids to possibly more dwarf planets," stated Harvard astronomer Pavlos Protopapas

"By the end of the survey, we'll have an essentially complete census of everything brighter than the survey's limiting magnitude," said Holman. This corresponds to Kuiper Belt Objects about 180 miles in diameter or larger.

"Pan-STARRS-1 offers us a remarkable opportunity to study the outer solar system in unprecedented detail," said team member Ying-Tung Chen, a graduate student at the National Central University of Taiwan.

Pan-STARRS will allow planetary astronomers to locate many new Kuiper Belt Objects and characterize their orbits. This will provide a firmer understanding of the structure, dynamics, and evolution of the outer solar system. Pan-STARRS is also likely to be a productive tool for discovering new comets.

Pan-STARRS-1 is a 1.8-meter (71-inch) telescope featuring the world's largest digital camera -- a 1.4-gigapixel (1,400-megapixel) monster that can photograph an area of the sky as large as 36 full moons in a single exposure. PS1 became fully operational in June 2010.