Space News Thread - Comet Mystery Deepens

[brunota2003]

Since there seems to be a lot of news regarding space here recently...figured I'd start a "Space News" thread...it should help keep the Off-Topic forum from cluddering up so fast...plus if you need to catch up on recent space news, instead of digging for it, come here to find it... Ok...I will go first:

PASADENA, Calif. - A NASA spacecraft successfully slipped into orbit around Mars Friday, joining a trio of orbiters already circling the Red Planet.

Scientists cheered after the Mars Reconnaissance Orbiter emerged from the planet's shadow and signaled to NASA's Jet Propulsion Laboratory that the maneuver was a success.

"Oh I am very relieved," project manager Jim Graf said minutes later. "It was picture perfect."

The two-ton spacecraft is the most sophisticated ever to arrive at Mars and is expected to gather more data on the Red Planet than all previous Martian missions combined.

It will explore Mars in low orbit for four years and is expected to churn out the most detailed information ever about the planet and its climate and landscape.

In the fall, the orbiter will begin exploring the Martian atmosphere, scan the surface for evidence of ancient water and scout for future landing sites to send robotic and possibly human explorers.

The $720 million mission is managed by JPL in Pasadena.

After a seven-month, 310 million-mile journey, the orbiter arrived at Mars Friday for the risky orbit insertion phase. Project managers had been nervous because of Mars' reputation of swallowing scientific probes.

But the Reconnaissance Orbiter performed the move without problem.

As it neared the planet, it fired its main propulsion engines for 27 minutes to slow itself down so that the planet's gravity could pull it into orbit. At one point during the burn, the spacecraft disappeared behind Mars — as engineers had planned — and was temporarily out of radio contact with controllers.

Mission control was visibly tense as it awaited word from the orbiter, which reappeared and signaled that it had entered into an elliptical orbit around Mars that will swing it as close as 250 miles above the surface.

The spacecraft will spend seven months dipping into the upper atmosphere to shrink the orbit.

The successful mission was welcome news for NASA, which has a mixed record of putting spacecraft into orbit around Mars.

In the last 15 years, NASA lost two orbiters back-to-back — the Mars Observer in 1993 and the Mars Climate Orbiter in 1999 — during the orbit insertion phase.

The Reconnaissance Orbiter is the fourth eye on the Martian sky, joining NASA's Mars Global Surveyor and Mars Odyssey and the European Space Agency's Mars Express, which have been mapping the planet the past few years. On the surface, the NASA rovers Spirit and Opportunity, continue their robotic geology missions.

The newest orbiter is loaded with the most advanced science instruments ever sent to another planet including a telescopic camera to photograph the surface in unprecedented detail and radar to probe underground for ice and possible evidence of liquid water.

The spacecraft won't beam back images or data until November. Like previous space probes before it, it will seek for evidence of ancient water and other signs that the planet could have been hospitable to life.

It will also scan for potential spots to land the next generation of robotic rovers and determine whether human outposts can survive on the dusty planet.

Present-day Mars is dry and cold with large caps of frozen water at its poles, but scientists believe the planet once was warmer and wetter eons ago — conditions that might have been suitable for life.

During the mission's second phase, the orbiter will transmit data between Earth and Mars. It is expected to serve as a communication relay for the Phoenix Mars Scout, which will explore the icy north pole in 2008 and the Mars Science Laboratory, an advanced rover scheduled to launch in 2009.

The Reconnaissance Orbiter's primary mission will end in 2010.

[brunota2003]

Old Space-Shuttle Booster Rocket Tested 1 hour, 34 minutes ago



PROMONTORY, Utah - A 4 1/2-year-old space-shuttle booster rocket was test-fired by ATK Thiokol to determine the effects of age on the rocket motor components.

"Parts in the motor have been used in other rocket sets, and we were getting close to the maximum age of the boosters," said Nick Whitehead, who supervises motor and stage design for ATK Thiokol. "We brought this set back to test it because it has had extended exposure to the humid environment at the Kennedy Space Center."

Whitehead was optimistic about the test results.

"We won't really know until the reports are all done, but right now everything appears normal," he said.

Whitehead said a preliminary report of the stationary test will be prepared within a day and a full report is expected to be delivered to NASA in 120 days. Report data will be collected from 89 instrumentation channels throughout the rocket.

The tests are important for NASA as it prepares a new shuttle design, said company spokeswoman Melodie DeGuibert.

"Right now, NASA launches are all grounded as they redesign, but we expect to be the propulsion provider for the upcoming crew launch vehicle," DeGuibert said. "They are looking at utilizing our current solid rocket propulsion technology."

Thursday's test was attended by NASA astronaut Richard Linnehan, who has gone into space three times.

The static, or stationary, tests are carried out about twice a year, and have attracted crowds of up to 5,000 people.

This test was performed before a smaller crowd including students from Ogden's Da Vinci Academy and Ben Lomond High School.

The 126-foot-long booster rockets are made from reusable motors, which are refueled and assembled after being shipping by railroad to the launch site.

[brunota2003]

Astronomers announced today the discovery of a frigid extrasolar planet several times larger than Earth orbiting a small red dwarf star roughly 9,000 light years away.

The finding alters astronomers' perceptions of planetary system formation and the distribution of planets in the galaxy, suggesting that large rock-ice worlds might outnumber gas giants like Jupiter.


The newfound planet is about 13 times more massive than Earth and likely has an icy and rocky but barren terrestrial surface, and it is one of the coldest planets ever discovered outside of our solar system.


It orbits 250 million miles away from a red dwarf star, which is about half the size of our Sun and much cooler. The orbital distance is about the same as our solar system's asteroid belt is from the Sun.


Rocky and cold


The planet is similar in rocky structure to Earth and it is described a "super-Earth."


But being so far away from a red dwarf means that its surface temperature is an inhospitable -330 degrees Fahrenheit (-201 Celsius), about the same as Uranus. That's too cold for liquid water or life as we know it.


Further analysis of the system revealed the absence of Jupiter-like gas giants, and scientists suspect the system literally ran out of gas and failed to form any. This may have starved the newfound planet of the raw materials it needed to turn into a gas giant itself.


"This icy super-Earth dominates the region around its star that in our solar system is populated by the gas-giant planets, Jupiter and Saturn. We've never seen a system like this before, because we've never had the means to find them," said study author Andrew Gould of The Ohio State University and leader of the MicroFUN planet-searching team.


'Pretty common'


Planet formation theory predicts that small, cold planets should form easier than larger ones around big stars. A previous study suggests that about two-thirds of all star systems in the galaxy are red dwarf stars, so solar systems filled with super-Earths might be three times more common than those with giant Jupiters.


"These icy super-earths are pretty common," Gould said. "Roughly 35 percent of all stars have them."


While this is one of the coldest exoplanets ever discovered, it is not the smallest. Earlier this year astronomers announced the discovery of an exoplanet just 5.5 times Earth's mass. The previous record holder weighed in at 7.5 Earth masses.


"Our discovery suggests that different types of solar systems form around different types of stars," said Scott Gaudi of the Harvard-Smithsonian Center for Astrophysics. "Sun-like stars form Jupiters, while red dwarf stars form super-Earths. Larger A-type stars may even form brown dwarfs in their disks."


Brown dwarfs are dim, failed stars that straddle the mass range between gas planets and real stars.


Discovery details


Astronomers discovered this latest planet, catalogued as OGLE-2005-BLG-169lb, with a technique called microlensing, an effect where the gravity of a foreground star makes a more distant star appear brighter. If the foreground star is orbited by a planet, the planet's gravity can periodically warp the brightness of the background star by tiny amounts.


This shift is a telltale indicator of a planet, but is so brief that scientists must monitor the star closely and make multiple observations to confirm the planet's existence. In this case, the scientists were concerned that the warp wasn't caused by a planet, so they wrote a special computer program to speed up their models and confirm the existence of the Neptune-sized object.

The planet's existence was determined by researchers from the MicroFUN, OGLE (Optical Gravitational Lensing Experiment) projects and the MDM Observatory in Arizona. The group has submitted their findings for publication in the journal Astrophysical Journal Letters.

[Matt-hurricanewatcher]

Wow a planet 13 times the size of earth made out of rock in ice. So pretty much a Uranus sized planet which looks like venus or Mars.

[James]

Makes you realise just how much amazing stuff is out there...

[brunota2003]

Some pretty interesting news articles...normally dont read most of them...but...:

Stardust particles, made of 'fire and ice', deepen comet mystery Tue Mar 14, 9:18 AM ET

ATLANTA, United States (AFP) - The particles the Stardust probe brought back to Earth in January are a mixture of extremely hot and cold minerals pointing to a mixed origin of the Wild 2 comet, NASA scientists said.

"Remarkably enough, we have found fire and ice," said Donald Brownlee, Stardust chief investigator said in a statement on the NASA website that summed up a press conference held Monday at the Johnson Space Center (JSC) in Houston, Texas.

Rather than the balls of ice, dust and gas astrophysicists thought they were, comets turn out to be celestial bodies of complex and varied origins, said the University of Washington professor.

"It seems that comets are a mixture of materials formed at all temperatures, at places very near the early sun and at places very remote from it," said Michael Zolensky, Stardust curator and co-investigator at JSC.

The Wild 2 particles include olivine, a rock found in abundance in the green sand on some Hawaiian beaches. Its presence in the comet's dust trail was a surprise, scientists said. Olivine's components include iron, magnesium and other elements.

The Wild 2 samples have other high-temperature materials containing calcium, aluminum and titanium.

A Stardust capsule carrying a teaspoonful of space dust parachuted to Earth in the Utah desert on January 15 after a nearly seven-year journey across 4.63 billion kilometers (2.88 billion miles).

The dust was captured in super-light "aerogel", a sturdy, sponge-like solid carried on the spacecraft. Some of the interstellar particles were collected as the craft passed through the aura of the comet Wild Two. The rest were harvested along the course of the Stardust craft's journey.

The interstellar dust is being analyzed by some 150 scientists around the world, Brownlee said, adding that the laboratories were provided the samples for free.

Millions of comets encircle the sun and as they near the star, the solar heat melts the ice, leaving a trail of dust that is illuminated as a long tail.

Linked in superstitious minds with great events, good and bad, comets are equally beguiling for astrophysicists, who believe they are the most primitive material from the early days of the solar system.

They are considered to be the leftovers from the massive cloud of gas and dust that condensed and then coagulated to form the sun, the planets and other parts of the solar system about 4.6 billion years ago.

Scientists say understanding the substance and structure of comets provides clues of how Earth came into being.