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Showing posts with label journal nature. Show all posts
Showing posts with label journal nature. Show all posts

Mars Reconnaissance Orbiter Mission Status Report

Posted by Esse-Jay | Posted in , , , , , | Posted on 12:00
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            ** Artist concept of Mars Reconnaissance Orbiter. Image credit: NASA/JPL**

PASADENA, Calif. -- Engineers for NASA's Mars Reconnaissance Orbiter project have stepped up the communication rate being received from the orbiter as an early step in the process of determining why the spacecraft spontaneously rebooted its computer on Aug. 26.

The latest reboot occurred at 5:42 a.m. Pacific Daylight Time (12:42 Universal Time) on Wednesday, Aug. 26.

Data received from the orbiter indicate that this reboot had a different signature from reboots in February and June of this year.

Three new pieces of information are available to guide the investigation. This latest reboot affected some memory locations that had not been affected by the earlier ones. Also, unlike those earlier reboots, this event occurred while the spacecraft was using its backup, "B Side," main computer. In early August, the orbiter unexpectedly switched itself from the "A Side" main computer to the "B Side" computer. And finally, the decreasing intervals between the four safe-mode events this year are also providing clues to the problem.

To help in identifying a root cause in case of a recurrence, engineers had programmed the spacecraft this month to frequently record engineering data onto non-volatile memory. That large amount of data now being received could give an improved record of spacecraft events leading up to the latest reboot.

The Mars Reconnaissance Orbiter currently has normal power, temperatures and battery charge. It remains in proper sun-pointed attitude and in high-rate communication with Earth. Safe mode is a precautionary status that spacecraft are programmed to enter when they sense conditions for which they do not know a more specific response. While in this mode, a spacecraft suspends non-essential activities pending further instructions from ground controllers.

"The spacecraft is stable and our priority now is to carefully work our way to understanding this anomaly, with the intent of preventing recurrences," Mars Reconnaissance Orbiter Project Manager Jim Erickson, at NASA's Jet Propulsion Laboratory, Pasadena, Calif., said Friday.

The Mars Reconnaissance Orbiter has been investigating Mars with six science instruments since it reached that planet in 2006. It has returned more data than all other current and past Mars missions combined.

JPL, a division of the California Institute of Technology in Pasadena, managed the Mars Reconnaissance Orbiter mission for NASA.

Provided by Jet Propulsion Laboratory, Pasadena, California.


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Found planet that shouldn't exist

Posted by Esse-Jay | Posted in , , , , , | Posted on 11:34
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The find, by an international team including the University of St Andrews, is so bizarre that odds on catching it at this late stage in its life were 1000-1. The 'huge new planet', found orbiting a star 1000 light years away, was discovered by the UK's WASP project, of which St Andrews is a founding member.

Newly-christened WASP-18b, the planet is so massive and so close to its host star that it is almost certain to spiral inwards to its destruction during the lifetime of the star. Researchers from St Andrews are currently calculating the rate at which tidal interactions between star and planet will eventually cause the planet's orbit to decay completely.






St Andrews' physicist, Professor Andrew Collier Cameron said, "This is another bizarre WASP planet discovery. The situation is analogous to the way tidal friction is gradually causing the earth's spin to slow down, and the Moon to spiral away from the earth.
"In this case, however, the spin of the star is slower than the orbit of the planet - so the star should be spinning up, and the planet spiralling in."
WASP-18b is ten times the mass of Jupiter and orbits its star in less than one Earth-day. The new planet belongs to a now-common class of extrasolar planets known as 'hot Jupiters' - massive planets thought to have formed far from their host stars that migrated inwards over time.
The discovery, led by Keele University's Coel Hellier, suggests that WASP-18's parent star is about a billion years old - making the likelihood of observing WASP-18b about one in a thousand.
If the planet's remaining life is as short as predicted, its orbital decay should be measurable within a decade.
Professor Cameron continued, "We don't yet know how long the planet will survive, because we don't understand fully how tides operate on the Sun and other stars. It could be half a million years, or half a billion. But if it's spiralling in quickly, we should be able to see measurable changes in the orbit within ten years."


Provided by University of St Andrews




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Hubble Captures Rare Jupiter Collision

Posted by Esse-Jay | Posted in , , , | Posted on 11:11
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NASA scientists have interrupted the checkout and calibration of the Hubble Space Telescope to aim the recently refurbished observatory at a new expanding spot on the giant planet Jupiter. The spot, caused by the impact of a comet or an asteroid, is changing day to day in the planet's cloud tops. For the past several days the world's largest telescopes have been trained on Jupiter. Not to miss any detail of the potentially new science in the unfolding drama 360 million miles away.
The Hubble picture, taken on July 23, is the sharpest visible-light picture taken of the impact feature. The observations were made with Hubble's new camera, the Wide Field Camera 3.

Discovered by Australian amateur astronomer Anthony Wesley on Sunday, July 19, the spot was created when a small object plunged into Jupiter's atmosphere and disintegrated. The only other time in history such a feature has been seen on Jupiter was 15 years ago. This is strikingly similar to the comet Shoemaker Levy 9 that impacted Jupiter in July 1994.
It is believed that impacts of this magnitude are rare so we are very fortunate to see it with Hubble, also the details seen in the Hubble view shows a  lumpiness to the debris plume caused by turbulence in Jupiter's atmosphere. The spot is presently twice the length of the United States.

Simon-Miller of NASA's Goddard Space Flight Center estimated that the diameter of the object that slammed into Jupiter was at least the size of several football fields. The force of the explosion on Jupiter was thousands of times more powerful than the suspected comet or asteroid that exploded over the Tunguska River Valley in Siberia in June 1908.
The WFC3, installed by the STS-125 astronauts in May, is not yet fully calibrated. So while it is possible to obtain celestial images, the camera's full power cannot yet be realized for most observations. The WFC3 can still return meaningful science images that will complement the Jupiter pictures being taken with ground-based telescopes. This is a natural color image of Jupiter as seen in visible light.

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