(Note: Not yet updated for Spring 2005 semester; will do so soon.)
NASA announced yesterday the discovery of three new planets orbiting stars other than the Sun, bringing the total number of known extrasolar planets to 124. The unusual aspect of the new planets is that they are less massive than those previously found, more closely resembling Uranus or Neptune than Jupiter - but still far more massive than the Earth (and orbiting too close to their parent stars for any realistic possibility that life could exist there). All three of the new planets were found by detecting (through the Doppler effect) very small motions of the parent stars, caused by the gravitational influence of the planets. For more information, go to the official NASA press release.
A NASA mission called Genesis has been orbiting the Sun for two years and is now sending a capsule back to Earth containing samples of atomic particles from the solar wind, a stream of electrons and ions that is emanating from the Sun. While the spacecraft was in orbit around Lagrange Point 1, a point between Earth and the sun where the gravity of both bodies is balanced, it collected particles of the solar wind in specially designed high purity wafers. After two years, the sample collectors were re-stowed and returned to Earth for a mid-air recovery of the sample return capsule. The samples will be stored and cataloged under ultra-pure cleanroom conditions and made available to the world scientific community for study. Learn more at the NASA/JPL website on the Genesis Mission.
The Genesis spacecraft re-entered the atmosphere over Utah right on schedule, on September 8 - but the explosive charge that was supposed to trigger the parachute to open failed and the spacecraft impacted the ground at high speed (just under 200 miles per hour). At the present time NASA scientists are fastidiously sorting through the debris, and entertain some hope that at least some of the captured solar wind particles can be retrieved unharmed and uncontaminated. For more on this, visit the NASA Web site where the failure is discussed.
The NASA-funded Stratospheric Observatory for Infrared Astronomy (SOFIA), consisting of a 2.5-m telescope mounted in a Boeing 747 aircraft, has been under development for several years and is approaching its anticipated 2005 first flight. Today NASA announced that the telescope has been successfully operated from the ground, making its first observations of stars. For information on the details of the instrument and its scientific goals, visit the SOFIA web site.
The two small robotic rovers on Mars, called Spirit and Opportunity, have already exceeded all expectations by continuing to operate on the surface of Mars for months longer than originally planned. So long, in fact, that they were still alive and well when Mars reached the point in its orbit called superior conjunction, meaning that the planet passed behind the Sun as seen from Earth. Because this interrupted radio communications with the Rovers, NASA decided to essentially park them, commanding them to stay still and not move for a period of time. This press release announces that Mars is now sufficiently clear of the Sun that communications with the Rovers are back to normal, and once again they are being programmed to crawl over the Martian surface, obtaining data on rocks and minerals.
Data from the European Space Agency's XMM-Newton Observatory have revealed a merger in progress, between two large clusters of galaxies. The result will be a much larger cluster, usually called a supercluster of galaxies, one of the largest objects in the universe. Read all about it on ESA's news web site.
NASA has awarded study funding to Professor Webster Cash of our APS Department for further development of a novel and imaginative instrument capable of detecting planets as small as the Earth orbiting as close as 0.1 AU from their parent stars. Cash's proposal calls for an orbiting pair of satellites, one of which would consist of a 100-m screen with a 10-m (about 30 foot) hole in its center (that is the pinhole), the second satellite, coasting about 1200 km behind, equipped with a telescope to record the image from the pinhole. This device will be diffraction limited, whihc means for a 10-m aperture a resolving power of about 0.01 arcsecond, sufficient to separate a close-in planet from its star. That could be achieved by any space-based 10-m telescope, but the key to this proposed instrument is that the large screen and the pinhole allows light from the star to be blocked out so completely that its planet, which will be many millions of times fainter than the star, can still be seen. For more see the CU press release and related articles (you can find many popular-level articles about this by just doing a Google search for "New Worlds Imager") .
NASA has announced new results from the Mars Rovers, small robots currently crawling around on the Martian surfec, regarding the now widely-accepted notion that Mars once had running as well as standing liquid water on its surfface, in the form of large lakes and many rivers. The new results show images of cracked surface soil suggesting of secondary immersion in water (after the original rocky surface had formed in water), much like a dried and cracked lake bed or tidal shore on Earth. For more, see the NASA press release on this.
The Genesis payload crashed hard into the Utah desert last month when its parachute failed to deploy, and scientists thought all was lost; i.e., that the collection of solar wind particles being brought to Earth after a three-year Sun-orbiting mission had all been destroyed by the impact. But now Genesis mission scientists have found to their delight that most of the sample containers managed to survive the crash. The samples have been transferred to the Lunar and Planetary Institute in Houston, where teams of scientists will analylze them in the months to come. Look here for more information.
In 1604 a "new star" or nova appeared in the sky, and was observed by Johannes Kepler among many others. Now this is cited as Supernova 1604A, or simply Kepler's Supernova. Today astronomers distinguish between novae and and supernovae, where the latter involves the complete annihilation of a star, releasing as much energy in a moment as the Sun will emit in its entire 10-billion year lifetime. Supernovae occur about once avery 30 to 50 years in a galaxy like ours, but the event of 1604 is the last naked-eye supernovae seen - so statistically speaking, we are overdue for the next one. The news is that a combination of data from three of NASA's orbiting "Great Observatories," the Hubble Space Telescope, the Spitzer Space Telescope (infrared), and the Chandra X-Ray Observatory, have been combined to produce a wonderful image of the remnant of Kepler's supernova, which you can find at this link.
Last Tuesday (October 5) a meteorite crashed into the side yard of a house in Berthoud and was immediately recovered. Now it is in the hands of CU, and will eventually be on display at Fiske Planetarium. But with luck we will get a chance to look at it in our classroom later this week. Watch for a news release dated today, originating from the Berthoud newspaper - and come to class Wednesday to get a close-up look.
Yesterday the Cassini mission orbiter made its closest approach to Saturn's giant moon Titan, flying above its atmosphere at only 745 miles altitude (relative to the solid surface of the moon, below the clouds). Using infrared and radar imagers, Cassini sent back pictures of light and dark areas on the surface of Titan, suggestive of continental highlands and lower-lying seas or lakes, which might be made of semi-liquid hydrocarbons, liquid nitrogen, or liquid methane. For more, see either the general Cassini mission web page or the web site of the Cassini imaging team, headed by Dr. Carolyn Porco of the Space Science Institute in Boulder.
NASA's Swift mission (named for the rapid-flying bird) was launched from Cape Canaveral on Saturday, after a series of short delays due to technical glitches and weather. All systems are normal and expectations are high. Swift is designed to make rapid follow-up observations of gamma ray bursts, which occur all over the sky at a rate of around once per day. These hugely energetic events are known to take place in very distant galaxies, and many of those observed occurred millions to billions of years ago, with the radiation just reaching us now. The current leading hypothesis is that these are the high-energy emissions from "hypernovae," referring to a class of supernova (massive star explosion) not yet observed nearby. The Swift mission has the capability of detecting gamma ray bursts, recording rough positional informatioin in a matter of seconds and transmitting the information to the ground rapidly so that automated optical telescopes can quickly observe the target; and then quickly re-orientating itself so that theX-ray, optical and ultraviolet telescopes on board can obtain follow-up observations within seconds of the burst. For more information, go to the official Swift mission web site.
The latest issue of the science journal called Science contains several articles by members of the Mars Rover science teams. Among the key results is a summary of the evidence that Mars once had liquid water lakes or oceans. Much of this evidence is based on minerals identified by the Martian rovers which are known to form in water but not in dry conditions. For more, go to the Science web site.
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