From JPL: “NASA’s Asteroid-Hunting Spacecraft a Discovery Machine”

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JPL-Caltech

June 5, 2017

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov

Dwayne Brown
NASA Headquarters, Washington
202-358-1726
dwayne.c.brown@nasa.gov

Laurie Cantillo
NASA Headquarters, Washington
202-358-1077
laura.l.cantillo@nasa.gov

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This movie shows the progression of NASA’s Near-Earth Object Wide-field Survey Explorer (NEOWISE) investigation for the mission’s first three years following its restart in December 2013.

NASA/WISE Telescope

Green circles represent near-Earth objects (asteroids and comets that come within 1.3 astronomical units of the sun; one astronomical unit is Earth’s distance from the sun). Yellow squares represent comets. Gray dots represent all other asteroids, which are mostly in the main asteroid belt between Mars and Jupiter. The orbits of Mercury, Venus, Earth and Mars are shown.

The spacecraft has characterized a total of 693 near-Earth objects since the mission was restarted in December 2013. Of these, 114 are new discoveries.

JPL manages NEOWISE for NASA’s Science Mission Directorate at the agency’s headquarters in Washington. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

For more information about NEOWISE, visit http://www.nasa.gov/neowise

More information about asteroids and near-Earth objects is at http://www.jpl.nasa.gov/asteroidwatch.

NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission has released its third year of survey data, with the spacecraft discovering 97 previously unknown celestial objects in the last year. Of those, 28 were near-Earth objects, 64 were main belt asteroids and five were comets.

The spacecraft has now characterized a total of 693 near-Earth objects since the mission was re-started in December 2013. Of these, 114 are new. The NEOWISE team has released an animation depicting this solar system survey’s discoveries and characterizations for its third year of operations.

“NEOWISE is not only discovering previously uncharted asteroids and comets, but it is providing excellent data on many of those already in our catalog,” said Amy Mainzer, NEOWISE principal investigator from NASA’s Jet Propulsion Laboratory in Pasadena, California. “It is also proving to be an invaluable tool in in the refining and perfecting of techniques for near-Earth object discovery and characterization by a space-based infrared observatory.”

Near-Earth objects (NEOs) are comets and asteroids that have been nudged by the gravitational attraction of the planets in our solar system into orbits that allow them to enter Earth’s neighborhood. Ten of the objects discovered by NEOWISE in the past year have been classified as potentially hazardous asteroids, based on their size and their orbits.

More than 2.6 million infrared images of the sky were collected in the third year of operations by NEOWISE. These data are combined with the Year 1 and 2 NEOWISE data into a single archive that contains approximately 7.7 million sets of images and a database of more than 57.7 billion source detections extracted from those images.

A newly discovered Jupiter-like world is so hot, it’s being vaporized by its own star.

With a dayside temperature of more than 7,800 degrees Fahrenheit (4,600 Kelvin), KELT-9b is a planet that is hotter than most stars. But its blue A-type star, called KELT-9, is even hotter — in fact, it is probably unraveling the planet through evaporation.

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Artist conception of the KELT-9 system. The host star is a hot, rapidly rotating A-type star that is about 2.5 times more massive and almost twice as hot as our sun. Credit: NASA/JPL-Caltech/R. Hurt (IPAC)

“This is the hottest gas giant planet that has ever been discovered,” said Scott Gaudi, astronomy professor at The Ohio State University in Columbus, who led a study on the topic. He worked on this study while on sabbatical at NASA’s Jet Propulsion Laboratory, Pasadena, California. The unusual planet is described in the journal Nature and at a presentation at the American Astronomical Society summer meeting this week in Austin, Texas.

KELT-9b is 2.8 times more massive than Jupiter, but only half as dense. Scientists would expect the planet to have a smaller radius, but the extreme radiation from its host star has caused the planet’s atmosphere to puff up like a balloon.

Because the planet is tidally locked to its star — as the moon is to Earth — one side of the planet is always facing toward the star, and one side is in perpetual darkness. Molecules such as water, carbon dioxide and methane can’t form on the dayside because it is bombarded by too much ultraviolet radiation. The properties of the nightside are still mysterious — molecules may be able to form there, but probably only temporarily.

“It’s a planet by any of the typical definitions of mass, but its atmosphere is almost certainly unlike any other planet we’ve ever seen just because of the temperature of its dayside,” Gaudi said.

The KELT-9 star is only 300 million years old, which is young in star time. It is more than twice as large, and nearly twice as hot, as our sun. Given that the planet’s atmosphere is constantly blasted with high levels of ultraviolet radiation, the planet may even be shedding a tail of evaporated planetary material like a comet.

“KELT-9 radiates so much ultraviolet radiation that it may completely evaporate the planet,” said Keivan Stassun, a professor of physics and astronomy at Vanderbilt University, Nashville, Tennessee, who directed the study with Gaudi.

But this scenario assumes the star doesn’t grow to engulf the planet first.

“KELT-9 will swell to become a red giant star in a few hundred million years,” said Stassun. “The long-term prospects for life, or real estate for that matter, on KELT-9b are not looking good.”

The planet is also unusual in that it orbits perpendicular to the spin axis of the star. That would be analogous to the planet orbiting perpendicular to the plane of our solar system. One “year” on this planet is less than two days.

KELT-9b is nowhere close to habitable, but Gaudi said there’s a good reason to study worlds that are unlivable in the extreme.

“As has been highlighted by the recent discoveries from the MEarth collaboration, the planet around Proxima Centauri, and the astonishing system discovered around TRAPPIST-1, the astronomical community is clearly focused on finding Earthlike planets around small, cooler stars like our sun.

Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

The TRAPPIST-1 star, an ultracool dwarf, is orbited by seven Earth-size planets (NASA).

They are easy targets and there’s a lot that can be learned about potentially habitable planets orbiting very low-mass stars in general. On the other hand, because KELT-9b’s host star is bigger and hotter than the sun, it complements those efforts and provides a kind of touchstone for understanding how planetary systems form around hot, massive stars,” Gaudi said.

The KELT-9b planet was found using one of the two telescopes called KELT, or Kilodegree Extremely Little Telescope.

Kelt North Telescope In Arizona at Winer Observatory by Ohio State University

In late May and early June 2016, astronomers using the KELT-North telescope at Winer Observatory in Arizona noticed a tiny drop in the star’s brightness — only about half of one percent — which indicated that a planet may have passed in front of the star. The brightness dipped once every 1.5 days, which means the planet completes a “yearly” circuit around its star every 1.5 days.

Subsequent observations confirmed the signal to be due to a planet, and revealed it to be what astronomers call a “hot Jupiter” — the kind of planet the KELT telescopes are designed to spot.

Astronomers at Ohio State, Lehigh University in Bethlehem, Pennsylvania, and Vanderbilt jointly operate two KELTs (one each in the northern and southern hemispheres) to fill a large gap in the available technologies for finding exoplanets. Other telescopes are designed to look at very faint stars in much smaller sections of the sky, and at very high resolution.

KELT South robotic telescope, Southerland, South Africa

The KELTs, in contrast, look at millions of very bright stars at once, over broad sections of sky, and at low resolution.

“This discovery is a testament to the discovery power of small telescopes, and the ability of citizen scientists to directly contribute to cutting-edge scientific research,” said Joshua Pepper, astronomer and assistant professor of physics at Lehigh University in Bethlehem, Pennsylvania, who built the two KELT telescopes.

The astronomers hope to take a closer look at KELT-9b with other telescopes — including NASA’s Spitzer and Hubble space telescopes, and eventually the James Webb Space Telescope, which is scheduled to launch in 2018.

NASA/Spitzer Telescope

NASA/ESA Hubble Telescope

NASA/ESA/CSA Webb Telescope annotated

Observations with Hubble would enable them to see if the planet really does have a cometary tail, and allow them to determine how much longer that planet will survive its current hellish condition.

“Thanks to this planet’s star-like heat, it is an exceptional target to observe at all wavelengths, from ultraviolet to infrared, in both transit and eclipse. Such observations will allow us to get as complete a view of its atmosphere as is possible for a planet outside our solar system,” said Knicole Colon, paper co-author who was based at NASA Ames Research Center in California’s Silicon Valley during the time of this study.

The study was largely funded by the National Science Foundation (NSF) through an NSF CAREER Grant, NSF PAARE Grant and an NSF Graduate Research Fellowship. Additional support came from NASA via the Jet Propulsion Laboratory and the Exoplanet Exploration Program; the Harvard Future Faculty Leaders Postdoctoral Fellowship; Theodore Dunham, Jr., Grant from the Fund for Astronomical Research; and the Japan Society for the Promotion of Science.

For more information about exoplanets, visit:

https://exoplanets.nasa.gov

See the full article here .

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Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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