Login
New User

Welcome to AOAS.ORG
Monday, May 29 2017 @ 03:01 pm EDT

Email Article To a Friend View Printable Version

A DIRECT HIT! DEEP IMPACT SLAMS 9P/TEMPLE 1

Lunar & Planetary
In the early morning hours of July 4 at approximately 12:52 A.M., an 820 pound copper projectile released from the NASA Deep Impact spacecraft just 24 hours earlier smashed into comet 9P/ Temple 1. The projectile struck the comet at an impact speed of roughly 37,000 mph with hopes of creating a huge impact crater thereby uncovering the comet's icy innards. It's the stuff inside comets that scientists want most to see and study, and judging by the gigantic plume of material which rose from the comet surface as the impactor hit, they should now get exactly what they wanted.

It's believed that comets are "left-over" remnants from the creation of the solar system. If the theory is correct, the material blown off the comet from this high-speed impact will give scientists their first ever clues as to exactly what the early solar nebula was made of, as well as the proportions in which those materials exist. As the time drew near for this cosmic fireworks show to begin, the tension in the JPL control room was evident. That tension turned to jubilant shouts and cries of congratulations as the control room realized that this first-of-its-kind mission had been a smashing success.

As the next few days pass, the world will see a wealth of images from an armada of space-based and Earth-based telescopes. The best views came from the Deep Impact mother ship as well as from the Impactor craft itself as its onboard cameras took pictures right up until the final three seconds of its existence. The mother ship's onboard instruments then gathered data of the comet's composition from the debris ejected by the impact. At the same time its cameras captured the rapidly evolving views of the comet surface where the Impactor was vaporized by the collision that created a huge crater.

Everything went exactly as planned and a mountain of data from this impact is being gathered by nearly every available telescopic instrument from around the world. When all is said and done we may finally find the answers that mankind has sought since the dawn of history…. Just what is a comet, anyway?

This image shows the Deep Impact mother ship's view as it sailed safely past the area of impact. The huge plume of material flying away from the comet surface was considerably more spectacular than anyone would have hoped for, and truly gave this mission the Fourth of July "fireworks" performance that all the world of science had wanted and waited to see.

More images are available on our aoas.org website in the Photo Gallery under "Science Photos". Many more images will be added to this first set of images as they are released by NASA over the coming days and weeks.
Email Article To a Friend View Printable Version

Observing and Drawing a Shadow Transit on Jupiter

Lunar & Planetary
When I discovered on the Sky & Telescope web site that a double shadow transit would take place on Jupiter the evening and early morning hours of June 9, 2005, I decided I wanted to try and observe and record the my observations of the Jovian moons Europa and Io as they crossed the face of Jupiter. When I set up my telescope at about 11:30 that evening, I noticed the entire sky was cloudy. According to the NWS (National Weather Service) the weather was supposed to be clear. The clouds were starting to move out by the time the transit of Europa’s shadow started to appear at approximately 12:20 AM of June 10th. I had to wait another 20 minutes before I could see through a clear patch of sky to begin my observation and my sketches.

As I began my observation, I could see that the first shadow of the two was just visible on the far right side of Jupiter in the lower of the two equatorial cloud belts. At about the same time I noticed a tiny speck on the far left side of the planet’s limb. At first I mistook this to be one of the moons about to disappear behind the planet.

But as time progressed, I realized that the tiny moon was exiting from the face of the planet and that told me that I was seeing Europa and its shadow. Shortly thereafter, a cloud bank moved over the planet and ended my observations for a while.

By 1:20 AM when I ventured outside once again, the sky had again cleared. I knew it wouldn’t last long, however, since I saw lightning off to the west. When I found Jupiter once again I could then see 2 black spots in Jupiter’s lower belt. I estimate that the two shadows were separated by about one-third the overall width of Jupiter. By now I could also see that Io had joined Europa off the left edge of the planet. Ganymede could be seen on the same side but much farther out from the planet. From what I’ve read, seeing both Europa and Io at the same time that I could see their respective shadows on the face of Jupiter is a rare thing. This realization just adds a nice topper to my observation and sketches of the King of the Planets. A little perserverance and patience rewarded me with a view and a pair of drawings that I'll never forget.
Email Article To a Friend View Printable Version

New Moon Found in Saturn's Rings

Lunar & Planetary
The international Cassini spacecraft has spied a tiny new moon hidden in a gap in Saturn's outer ring, scientists said.

The moon was spotted earlier this month in the center of the Keeler gap, making waves in the gap edges as it orbits. Tentatively called S/2005 S1, the moon measures four miles across and is about 85,000 miles from the center of Saturn.

More observations are needed to determine the shape of the moon's orbit, but preliminary findings show it is in the middle of the gap, Joseph Spitale, a planetary scientist at the Space Science Institute in Boulder, Colo., said Tuesday.

S/2005 S1 is the second moon known to exist within Saturn's shimmering rings. The other is Pan, which orbits in the Encke gap. All of Saturn's other known moons are outside the main ring system.

The $3.3 billion Cassini mission, funded by NASA and the European and Italian space agencies, was launched in 1997 and took seven years to reach Saturn.

Cassini/Huygens Home Page

Email Article To a Friend View Printable Version

Question about water and space

Lunar & PlanetaryHey everybody. I gave presentations to my daughters 4th grade science classes yesterday and as usual, the kids never fail to amaze me with their level of knowledge and the questions that they ask. I had talked briefly about the presence of ice in comets and in the rings of Saturn. I was then asked where the water comes from to which I had no answer. Can anybody tell me how water is created and does any reside in the innerstellar world of space? They also asked what the effect to earth would be if Jupiter blew up and what color would Uranus be if it wasn't blue. There were numerous extremely good questions and although I could answer most, I will need to study up on the finer details of the planets. I was lucky enough to do a little research before hand and know that Jupiter is now up to 63 moons. I had a great time and the kids seamed to really enjoy it as well. The 50 minutes for each class passed by in an instant. One class, I was only a 4th of the way thru my presentation and the teacher informed that there were only 10 minutes left. Well, lunch break is over but if anybody can help me out, I would appreciate any contributions to the water questions.

Answers as best I can give them.........by Bob Moody

Water exists by the combination of the elements that make it up, namely, one atom of oxygen bound to two atoms of hydrogen. We know that hydrogen is the most abundant element in the universe, and we believe we understand that oxygen came about as a result of the deaths of so-called "first-generation stars". These are stars which were made up almost exclusively of hydrogen and helium, with a thin sprinkling of lithium. These three were the original elements from the creation of the universe, and everything on the Periodic Table of Elements above these three elements have come about as the result of large first-generation stars which went supernova and literally "cooked up" the heavier elements during those supernova explosions. It takes titanic explosions with super-hot temperatures to forge the heavy elements.

Click "Read more" for the rest of this explanation.....
Email Article To a Friend View Printable Version

Earth's Moon: Still A Puzzle

Lunar & PlanetaryBy Leonard David
Senior Space Writer
SPACE.com


LEAGUE CITY, TEXAS -- Planet Earth's natural satellite has got a grip on scientists. The charisma of the Moon is made more so by many unanswered questions, even after Apollo moonwalkers went the distance to study the nearby, crater-pocked globe. Not only the U.S., but European, Indian, Japanese and Chinese probes are being readied for a new scientific assault on the Moon, hoping to glean insight about lunar ice, the Moon's cratering history, and even how that big, dusty ball of rock got there in the first place. Surprisingly, Apollo expeditions at $25 billion not only scratched the lunar surface but also promoted new question? That fact was clearly in evidence at the 36th Lunar and Planetary Science Conference (LPSC), held here March 14-18 and co-sponsored by the Lunar and Planetary Institute and NASA's Johnson Space Center.

Luna Incognita

Even to the untrained eye, just looking at the bruised and battered Moon suggests it has a tale to tell. "The Moon is like a witness plate. We have an impact recordwe just have to play the record," said Paul Lucey a professor at the Hawai'i Institute of Geophysics and Planetology at the University of Hawai'i in Honolulu. The Moon offers insight into how impacts shaped the Earth and played a role in the formation of life here on Earth, he said. "Ask not what astrobiology can do for the Moonask rather what the Moon can do for astrobiology," Lucey advised. Additionally, Lucey said, the Moon's poles are "luna incognita"—unknown and unexplored territory. "It all boils down to the fact that the tilt of the Moon with respect to the Sun is so littlecraters there can remain permanently shaded from the Sun." These craters are dubbed "cold traps"—locales of super-chilly temperatures—perhaps even colder than measurements made in the Saturn system, Lucey told SPACE.com. What's key is the idea that Moon-impacting comets unleashed their vast reservoirs of chemistry into the lunar environment. Along with water ice, molecules of methane, maybe ammonia and carbon dioxide, among other comet constituents, migrated like celestial holes in one into those cold, Sun-shy craters. "All kinds of things could potentially go there," Lucey noted.
Email Article To a Friend View Printable Version

Huygens Base – A Successful Landing on another World

The world today marvels at the first ever images of the surface of Saturn’s largest moon, Titan. Bigger than the planets Mercury or Pluto, Titan has long been known to have a very thick atmosphere composed of organic compounds and deadly gases. With the January 14, 2005 landing of the Huygens probe on the surface of Titan, mankind will have only just begun to scratch the surface of the secrets this mysterious world holds.

The Huygens probe rode piggyback aboard the Cassini spacecraft for seven long years until it was released to drift on its own towards Titan on Christmas Eve, 2004. The probe was gently pushed and spun simultaneously away from Cassini to provide more stability for that moment when it would enter the outer layers of Titan’s atmosphere in the early morning hours (local time) of January 14, 2005. A huge radio telescope at Greenbank, West Virginia picked up a faint signal from the compact-car-sized probe at around 4:37AM announcing the successful emergence of the probe's transmission antenna. This antenna could only have been extended if the heat shield and parachute system were working properly, thereby indicating that the mission had begun as planned.

As the probe continued down through the nearly 100-mile-thick atmosphere, two more parachutes would be deployed at specific times and altitudes to allow Huygens to “sniff”, “feel”, “hear” and “see” what the composition of Titan’s atmosphere actually was. All of the instruments operated as planned except for one data relay channel, and at around 7:00AM local time the probe touched down on Titan as planned.

The Cassini spacecraft pointed itself towards the surface of Titan to pick up the weak signals from Huygens, and then relayed those signals back to NASA’s Deep Space Network, a system of large radio telescopes stationed around the Earth to allow nearly continuous reception of data from the Huygens and Cassini team. After the 1hr 7minute trip from Titan at the speed of light, the radio transmissions were relayed from the DSN to the European Space Agency’s control facilities at Darmstadt, Germany. The raw images were processed only slightly and were then quickly released to a waiting world of scientists and curious onlookers eager to see for themselves what the surface of this forbidding world looked like. The defective data channel resulted in only 350 images being returned instead of 700 that could have been returned, but these images still give a most intriguing look at the hidden surface of Titan.
Email Article To a Friend View Printable Version

Near-Earth Asteroid 2004 MN4 Reaches Highest Score To Date On Hazard Scale

Lunar & PlanetaryDon Yeomans, Steve Chesley and Paul Chodas
NASA's Near Earth Object Program Office
December 23, 2004


A recently rediscovered 400-meter Near-Earth Asteroid (NEA) is predicted to pass near the Earth on 13 April 2029. The flyby distance is uncertain and an Earth impact cannot yet be ruled out. The odds of impact, presently around 1 in 300, are unusual enough to merit special monitoring by astronomers, but should not be of public concern. These odds are likely to change on a day-to-day basis as new data are received. In all likelihood, the possibility of impact will eventually be eliminated as the asteroid continues to be tracked by astronomers around the world.
Email Article To a Friend View Printable Version

Awaiting the Huygens Probe Landing on Titan

European Space Agency releases the first image of Titan's surface on January 14, 2005. This image reveals "stubby channels running through an apparent shoreline into a "sea" or "lake" on the surface". Image was taken at an altitude of some 10 miles. (ESA Photo)
The Cassini/Huygens spacecraft will arguably begin the most significant portion of its long mission to the Ring World this Friday, Christmas Eve. The world will watch as the European Space Agency's Huygens probe will separate from the NASA Cassini mothership to begin a fall that will end with the touchdown of Huygens on the surface of Saturn's largest moon Titan on January 14th.

UPDATE 1: 12.25.04 Huygens has been successfully released and is on its way, alone, towards Titan.

UPDATE 2: TOUCHDOWN ON TITAN THIS MORNING, JAN 14TH! The Huygens probe will begin its journey into the outer layers of Titan's atmosphere at approximately 4:20 AM. The journey will take nearly 3 hours before the probe reaches the surface. The MORNING NEWS SHOWS should be carrying this event, and possibly carrying it LIVE!

"BONNE CHANCE", HUYGENS!!!

UPDATE 3: From the Robert C. Byrd Radio Telescope in Green Bank, West Virginia. "The 'carrier signal' has been detected and Huygens has entered the atmosphere of Titan, 11:37 Central European Time (4:37am CST)" !!!

SUCCESS! HUYGENS PROBE LANDS SAFELY; SENDS A "SCIENTIFIC BOUNTY OF INFORMATION"!!!

Email Article To a Friend View Printable Version

Science at Saturn - Cassini Delivers

The Cassini/Huygens spacecraft currently in orbit around Saturn has begun to send back spectacular images along with some early science results. After successfully entering orbit on the evening of June 30/July 1, Cassini has been busily imaging Saturn along with it's beautiful ring system and some of it's moons. The spacecraft skimmed a mere 11,200 miles above the cloud tops of Saturn, less than one-sixth of Saturn's diameter. This Orbital Insertion maneuver brought Cassini to its closest proximity to Saturn of the entire four-year mission.

During this maneuver, Cassini was aimed to pass through a narrow gap in Saturn's Rings known as the Encke Division. (the outermost, thin gap seen here)

While passing through the ring-plane, the craft's main antenna was positioned to absorb the brunt of the impacts of anything that might have been located within that seemingly empty gap. It was hardly empty! During the passage Cassini recorded more than 100,000 impacts in less than 5 minutes from tiny particles ranging in size from those of smoke particles to others perhaps as large as talcum powder. Cassini sustained little damage from this passage through the ring-plane.

Close-up of the Encke Division

While making this historic maneuver Cassini wasn't idle. Its cameras were constantly imaging the area through which it would pass and delivered some truly stunning pictures.
Email Article To a Friend View Printable Version

Cassini/Huygens Science Mission Set to Begin with Orbital Insertion at Saturn this Week

Lunar & PlanetaryBy Bob Moody (AOAS) and Gerrit Penning (ASSABFN)
UPDATE: July 1, 2004 Saturn Orbital Insertion a Success!
For the latest images, go to: http://saturn.jpl.nasa.gov/multimedia/images/latest/index.cfm


After a journey of seven years through the solar system, the Cassini spacecraft with its on-board Huygens probe, is set to arrive at Saturn this Wednesday/Thursday with a firing of the main engine for just over 100 minutes to slow it’s 50,000 mph speed by 1,300 mph to attain orbital insertion around the Ringed Planet. A slowing of it’s inertial speed will occur in stages to bring it into position for its scientific mission to study Saturn and its attendant moons, along with the release of the Huygens probe set for December 25, 2004. The Huygens probe will enter the thick atmosphere of Saturn’s largest moon Titan behind a sophisticated heat shield at a speed of nearly 44,000 mph in mid-January, 2005. After enduring temperatures of over 21,000 degrees Fahrenheit, the probe will release its main parachute at 900 mph at an altitude of about 110 miles above Titan’s surface, and then eject the protective heat shield. A separate drogue parachute will deploy at 85 miles altitude and carry the sophisticated probe down to the surface. The probe will take up to 1,100 pictures as it descends through the otherworldly atmosphere.

User Functions






Lost your password?

What's New

STORIES

No new stories

COMMENTS last 2 days

No new comments

LINKS last 2 weeks

No recent new links

Want It ALL?

Become a card-carrying member of AOAS. Paying dues gives you several advantages over other registered users, including a subscription to the club newsletter, an AOAS.ORG e-mail address, use of club materials, including books and telescopes, and access to the Coleman Observatory facilities. On top of all that, you also qualify for a 20% discount on all books at any Books-A-Million location.

To get your membership application, click here.