Sometimes I complain about the earthly weather, but mostly I like to post about astronomy and space events. Hope you enjoy the articles.
By: Susie77, 7:54 PM GMT on May 24, 2010
May 24, 2010
D.C. Agle/Jia-Rui Cook
Jet Propulsion Laboratory, Pasadena, Calif.
PHOENIX MARS LANDER DOES NOT PHONE HOME, NEW IMAGE SHOWS DAMAGE
PASADENA, Calif. -- NASA's Phoenix Mars Lander has ended operations
after repeated attempts to contact the spacecraft were unsuccessful.
A new image transmitted by NASA's Mars Reconnaissance Orbiter (MRO)
shows signs of severe ice damage to the lander's solar panels.
"The Phoenix spacecraft succeeded in its investigations and exceeded
its planned lifetime," said Fuk Li, manager of the Mars Exploration
Program at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
"Although its work is finished, analysis of information from
Phoenix's science activities will continue for some time to come."
Last week, NASA's Mars Odyssey orbiter flew over the Phoenix landing
site 61 times during a final attempt to communicate with the lander.
No transmission from the lander was detected. Phoenix also did not
communicate during 150 flights in three earlier listening campaigns
Earth-based research continues on discoveries Phoenix made during
summer conditions at the far-northern site where it landed May 25,
2008. The solar-powered lander completed its three-month mission and
kept working until sunlight waned two months later.
Phoenix was not designed to survive the dark, cold, icy winter.
However, the slim possibility Phoenix survived could not be
eliminated without listening for the lander after abundant sunshine
The MRO image of Phoenix taken this month by the High Resolution
Imaging Science Experiment, or HiRISE, camera on board the spacecraft
suggests the lander no longer casts shadows the way it did during its
"Before and after images are dramatically different," said Michael
Mellon of the University of Colorado in Boulder, a science team
member for both Phoenix and HiRISE. "The lander looks smaller, and
only a portion of the difference can be explained by accumulation of
dust on the lander, which makes its surfaces less distinguishable
from surrounding ground."
Apparent changes in the shadows cast by the lander are consistent with
predictions of how Phoenix could be damaged by harsh winter
conditions. It was anticipated that the weight of a carbon-dioxide
ice buildup could bend or break the lander's solar panels. Mellon
calculated hundreds of pounds of ice probably coated the lander in
During its mission, Phoenix confirmed and examined patches of the
widespread deposits of underground water ice detected by Odyssey and
identified a mineral called calcium carbonate that suggested
occasional presence of thawed water. The lander also found soil
chemistry with significant implications for life and observed falling
snow. The mission's biggest surprise was the discovery of
perchlorate, an oxidizing chemical on Earth that is food for some
microbes and potentially toxic for others.
"We found that the soil above the ice can act like a sponge, with
perchlorate scavenging water from the atmosphere and holding on to
it," said Peter Smith, Phoenix principal investigator at the
University of Arizona in Tucson. "You can have a thin film layer of
water capable of being a habitable environment. A micro-world at the
scale of grains of soil -- that's where the action is."
The perchlorate results are shaping subsequent astrobiology research,
as scientists investigate the implications of its antifreeze
properties and potential use as an energy source by microbes.
Discovery of the ice in the uppermost soil by Odyssey pointed the way
for Phoenix. More recently, the MRO detected numerous ice deposits in
middle latitudes at greater depth using radar and exposed on the
surface by fresh impact craters.
"Ice-rich environments are an even bigger part of the planet than we
thought," Smith said. "Somewhere in that vast region there are going
to be places that are more habitable than others."
NASA's MRO reached the planet in 2006 to begin a two-year primary
science mission. Its data show Mars had diverse wet environments at
many locations for differing durations during the planet's history,
and climate-change cycles persist into the present era. The mission
has returned more planetary data than all other Mars missions
Odyssey has been orbiting Mars since 2001. The mission also has played
important roles by supporting the twin Mars rovers Spirit and
Opportunity. The Phoenix mission was led by Smith at the University
of Arizona, with project management at JPL and development
partnership at Lockheed Martin in Denver. The University of Arizona
operates the HiRISE camera, which was built by Ball Aerospace and
Technologies Corp., in Boulder. Mars missions are managed by JPL for
NASA's Mars Exploration Program at NASA Headquarters in Washington.
For Phoenix information and images, visit:
By: Susie77, 9:34 PM GMT on May 13, 2010
A Rare Meeting of Planets and Spaceships
May 13, 2010: This weekend, Venus and the crescent Moon are gathering in the western sky for a spectacular conjunction, and they're not alone. The International Space Station and, very likely, space shuttle Atlantis will join them for a rare four-way meeting of spaceships and planets over many locations.
The show begins at sunset when Venus and the Moon emerge from the twilight in close proximity to one another. The Moon will be exquisitely slender, a 5% crescent on Saturday, May 15th (sky map), and a slightly fatter 10% crescent on Sunday, May 16th (sky map). Between the horns of the crescent, a ghostly image of the full Moon can be seen. That's "Earthshine"—the light of our own planet reflected back toward us by the Moon's dark terrain. In conjunction with Venus, a crescent Moon with Earthshine is regarded as one of the most beautiful sights in the heavens.
Into this tableau of surpassing beauty comes a spaceship--and maybe two!
The International Space Station is due to fly over many US towns and cities this weekend. The ISS appears just after sunset, about the same time as the Venus-Moon encounter, and it glides slowly across the sky shining as brightly as Venus herself. Check NASA's SkyWatch web site to see if you are favored with a flyby and to find out exactly when to look.
If the ISS appears over your hometown, Atlantis is likely to be there as well. The shuttle is scheduled to launch from the Kennedy Space Center on Friday, May 14th, at 2:20 pm EDT (updates). It would then spend the weekend catching up and docking with the ISS, appearing as a distinct point of light in company with the brighter space station. People who have seen double flybys of station and shuttle say it is even better than a Venus-Moon conjunction. Something about two spacecraft gliding silently together among the stars multiplies the beauty and wonder far beyond a factor of two.
This kind of station-shuttle double flyby is rare and soon to be a thing of the past. With only three flights remaining, the shuttle program is coming to an end. Indeed, this is the last scheduled flight of Atlantis and the last time it can appear side-by-side with the ISS in the night sky.
Atlantis's 12-day mission to the ISS helps lay the groundwork for the post-shuttle era. The orbiter will deliver thousands of pounds of supplies and spare parts, plus a new Russian research module and a European robotic arm. Astronauts plan to conduct three spacewalks totaling almost 20 hours to install batteries, an antenna and other hardware around the exterior of the station.
Flying through the sunset in the company of ISS, Venus and the crescent Moon is a nice way for Atlantis to wave goodbye.
Just don't forget to wave back
By: Susie77, 1:40 AM GMT on May 07, 2010
The Astronomy of Mother's Day
May 6, 2010: Looking for a great Mother's Day gift? Your search is over.
Mom wants a wake up call.
At dawn on Sunday, May 9th--Mother's Day--the crescent Moon and Jupiter are getting together for a lovely conjunction. Only 5o of arc will separate the two bright celestial delights as they hang together in the sunrise-colored sky. Mom doesn't even have to go outside. A glance out any east facing window will frame the show quite nicely: finder chart.
It may be worth noting how much more you can see with the aid of a small telescope. There are four big moons circling Jupiter—Io, Europa, Ganymede and Callisto, also known as the "Galilean satellites." Galileo discovered them 400 years ago using little more than a pirate's spyglass. The shadowy mountains and craters of the crescent Moon are also wonderful targets. Almost any optics you can find around the house will serve the purpose.
Only Mom can tell you if this is going too far at 5:30 in the morning.
In rare cases, Mom will not want to be woken up at the crack of doom--er, dawn. She might even refuse to get out of bed. If this happens, you'll need a backup plan.
Good news: There's also a nice display at sunset. Just as the sun is going down and the sky is fading to a deep cobalt blue, two bright lights will pop out of the twilight: Venus and Sirius. You can't miss them (especially Venus) shining halfway up the western sky: finder chart. They're not as close together as Jupiter and the Moon, but what they lack in proximity, they make up for in luminosity. Venus is the brightest of all planets and Sirius is the brightest of all stars. Set in twilight like jewels on velvet, Venus and Sirius are an unforgettable sight.
Remember that small telescope? Point it at Venus. The second planet from the sun shines with a pearly, unwavering glow that can only be described as otherworldly. Swing over to Sirius. The distant star sparkles like a diamond with sudden rainbow-colored glints. (Quick astronomy lesson: stars twinkle but planets do not. You're welcome, Mom.)
Heavenly pearls and diamonds are a nice way to wrap up the day—especially if you misjudged that wake up call.
Happy Mother's Day!