Search on for Tyche, believed to be largest planet in the solar system

By DAILY MAIL REPORTER

Last updated at 9:52 AM on 14th February 2011

Scientists believe they may have found a new planet in the far reaches of the solar system, up to four times the mass of Jupiter.

Its orbit would be thousands of times further from the Sun than the Earth’s – which could explain why it has so far remained undiscovered.

Data which could prove the existence of Tyche, a gas giant in the outer Oort Cloud, is set to be released later this year – although some believe proof has already been garnered by Nasa with its pace telescope, Wise, and is waiting to be pored over.

A new world? Astronomers believe a huge gas giant may be within the remote Oort Cloud region

Prof Daniel Whitmire from the University of Louisiana at Lafayette believes the data may prove Tyche’s existence within two years.

He told the Independent: ‘If it does, [fellow astrophysicist Prof John Matese] and I will be doing cartwheels. And that’s not easy at our age.’

He added he believes it will mainly be made of hydrogen and helium, with an atmosphere like Jupiter’s, with spots and rings and clouds, adding: ‘You’d also expect it to have moons. All the outer planets have them.’

He believes the planet is so huge, it will ahve a raised temperature left from its formation that will make it far higher than others, such as Pluto, at -73C, as ‘it takes an object this size a long time to cool off’.

Isolated: The Oort Cloud, where Tyche is believed to be, is a sphere with a radius of one light year

He and Prof Matese first suggested Tyche existed because of the angle comets were arriving, with a fifth of the expected number since 1898 entering higher than expected.

However, Tyche – if it exists – should also dislodge comets closer to home, from the inner Oort Cloud, but they have not been seen.

If confirmed, the status and name of the new planet – which would become the ninth and potentially the largest – would then have to be agreed by the International Astronomical Union.

Currently named Tyche, from the Greek goddess that governed the destiny of a city, its name may have to change, as it originated from a theory which has now been largely abandoned.

via Search on for Tyche, believed to be largest planet in the solar system | Mail Online.

NASA Sky-mapping Telescope Starts New Mission … Without Coolant

by Tariq Malik, SPACE.com Managing EditorDate: 05 October 2010 Time: 10:58 AM ET

An artist’s concept of the Wide-field Infrared Survey Explorer (WISE), a new NASA sky-mapper to scan the cosmos in infrared better than ever before. CREDIT: NASA/JPL

This story was updated at 12:10 p.m. ET.

A prolific NASA space telescope that is mapping the entire sky has run out of vital coolant needed to keep its detectors from warming up, but that hasn’t stopped its mission to seek out hidden asteroids, comets and other objects.

NASA’s Wide-field Infrared Survey Explorer, or WISE, is turning its camera eye on asteroids and comets within our solar system as part of its new NEOWISE Post-Cryogenic Mission. It allows the space telescope to continue scanning the cosmos despite the lack of frozen hydrogen onboard to keep its infrared detectors as cold as designed.

"Two of our four infrared detectors still work even at warmer temperatures, so we can use those bands to continue our hunt for asteroids and comets," said Amy Mainzer of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in a statement. Mainzer is leading the WISE telescope’s new mission.

NASA telescope’s new mission

The new NEOWISE mission, which takes its name from the near-Earth objects the telescope will hunt, is expected to last at least one month, and possibly as long as four months, NASA officials said.

To date, the WISE telescope has discovered 19 comets and more than 33,500 asteroids, including 120 near-Earth objects, which are objects with orbits that pass relatively close to Earth’s own orbit around the sun. The space observatory has taken about 1.8 million images of the sky using its main 16-inch (40-cm) telescope and four infrared detectors.

NASA launched the WISE telescope in December 2009 on a 10-month mission to completely map the entire sky. So far, it has mapped the sky 1 1/2 times.

In addition to asteroids and comets, the telescope observed odd cold stars called brown dwarfs, as well as hidden galaxies that are dark in visible light but shine bright in the infrared range of the light spectrum.

“WISE has provided a guidebook to the universe with thousands of targets worth viewing with a large telescope,” said WISE principal investigator Edward Wright of the University of California, Los Angeles. “We’re working on figuring out just how far away the brown dwarfs are, and how luminous the galaxies are.”

WISE telescope win

The longer mission is a big win for WISE telescope scientists.

In May, a NASA advisory panel recommended against extending the space telescope’s mission once its supply of hydrogen coolant ran dry.

At the time, NASA’s 2010 Astrophysics Senior Review Committee said there was not adequate scientific justification to continue the mission. That proposed three-month extension would have added $6.5 million to the telescope’s $320 million mission price tag.

NASA spokesperson J.D. Harrington told SPACE.com that after the WISE telescope’s coolant ran out late last week, the space agency’s planetary division decided to fund an extended mission to continue the search for near-Earth asteroids. The mission extension will cost about $400,000 for one month.

“At the end of that month, the collected data will be analyzed and a decision made as to whether it justifies extending the mission another three months,” Harrington said in an e-mail. “The possible four-month extension is what it would take to complete one full scan of the solar system.”

The NEOWISE mission is expected seek out more than nearby asteroids and comets. The extended mission should also allow the telescope to study the closest brown dwarfs to the sun, as well as revisit previous targets to see how they’ve moved since they were first spotted.

The science results from the first half of the WISE telescope’s sky survey will be released in spring 2011, NASA officials said.

“The science data collected by WISE will be used by the scientific community for decades,” said Jaya Bajpayee, NASA’s WISE program executive at the agency’s headquarters in Washington. “It will also provide a sky map for future observatories like NASA’s James Webb Space Telescope.”

via NASA Sky-mapping Telescope Starts New Mission … Without Coolant | Space.com.

Recent Studies Provide Different Estimates to Size of “Tenth Planet”

How Big Is 2003 UB313?

By Amir Alexander
February 1, 2006

Artist’s concept of 2003 UB313 Credit: Robert Hurt (IPAC)

How big is 2003 UB313 — the most distant known object in our solar system — often referred to as the “10th planet”? Ever since its discovery, the exact size of this object, nicknamed “Xena” by its discoverers, has exercised planetary scientists. In the past week, two different announcements gave conflicting answers to this question. One put 2003 UB313’s diameter first at almost precisely that of Pluto, the other at 30% greater than Pluto.

When it was first announced at a press conference in July 2005, Caltech’s Michael Brown, who led the team that discovered the object, estimated 2003 UB313’s diameter at around 2,700 kilometers (1,620 miles). This implied that it is substantially larger than Pluto, which has a diameter of 2,300 kilometers (1,380 miles), and consequently that it should be considered a “10th planet” in our solar system.

As Brown was quick to note at the time, however, size estimates based on visible light observations are notoriously inaccurate. The reason is that the brightness of an object viewed from Earth is dependent both on its size and its reflectivity, known as the object’s “albedo.” For a given observed brightness, an object with a higher albedo is smaller than an object with a low albedo. Without an independent measurement of either an object’s size or the albedo, there is no way to disentangle the two. Brown’s original size estimate was based on the assumption that 2003 UB313’s albedo is similar to Pluto’s. Since Pluto, which reflects 62% of the Sunlight that comes its way is one of the most reflective known bodies in the solar system, Brown’s assumption was, in fact, a conservative one.

One obvious way of determining the actual size of 2003 UB313 would be to resolve its disk in a telescope and measure it. As reported in the online journal Science NOW, in a public talk, Brown said that this was in fact accomplished recently by the Hubble Space Telescope (HST). Preliminary estimates based on this image suggested that 2003 UB313 was smaller than previously thought — in fact, barely bigger than Pluto. The surprising aspect of this find is that such a small diameter must imply a remarkably high albedo of 92%! Scientists have no idea of how or why the body would be so extraordinarily reflective. However, this report was premature, and Brown has since stated, “Contrary to rumors otherwise, we’re just in the preliminary stages of analyzing the HST data. When we are done we should have a very precise measurement. I hope that we will have the HST analysis done within perhaps a month, and I’ll be able to say more then.”

Using the Max Planck Millimeter Bolometer (MAMBO-2) at the IRAM 30-meter telescope in Pico Veleta, Spain, Bertoldi and his colleagues measured 2003 UB313’s radiation at the 1.2-millimeter wavelength between August 19 and 27, 2005. Since its surface temperature is about 25 kelvins (-248 degrees Celsius or -414 degrees Fahrenheit), they calculated that its diameter should be 3,094 kilometers (1,856 miles) — 30% greater than Pluto. This estimate has the additional advantage that it implies an albedo of 55%, very similar to Pluto’s 62%. In the Nature article, the authors note that the measurement of an object’s thermal radiation does depend, to a certain extent, on its rotation rate and the inclination of its orbit as viewed from Earth. But even taking the most “pessimistic” (and unlikely) estimates, Bertoldi’s team nevertheless arrived at a size estimate of 2,859 kilometers (1,715 miles) in diameter, still substantially larger than Pluto.

Though the exact diameter of 2003 UB313 is not yet known, the cumulative weight of evidence points to an object larger, perhaps substantially larger, than Pluto. This debate is no help at all to the International Astronomical Union, which is currently weighing the thorny and emotional question: “what is a planet?” If 2003 UB313 is larger than Pluto, is it a planet? If it is, what about other large trans-Neptunian objects? If it isn’t, then should its smaller kin Pluto be regarded as a planet? The answers are far from clear. But as evidence accumulates on the variety and complexity of objects in our own and other planetary systems, the old comfortable definitions are being stretched to their limits.

How Big Is 2003 UB313? – Planetary News | The Planetary Society.