The Cosmic Mirrorof News events across the Universe |
Compiled and written by Daniel Fischer, Skyweek - older "Mirrors" in the Archive - and find out what the future might bring! The latest issue! |
Current mission news: MGS (latest pictures!) + Cassini + Galileo + Prospector |
NASA selects Mercury orbiter, comet crasher as next Discovery missionsThe first spacecraft to go into orbit around the planet Mercury and another that will have an explosive encounter with a comet have been selected as the latest missions of NASA's Discovery Program! The Mercury Surface, Space Environment, Geochemistry and Ranging (Messenger) mission will launch in 2004. After performing two Venus flybys, Messenger will make two flybys of Mercury in 2008 before settling into orbit around the innermost planet in 2009.The other Discovery mission selected, Deep Impact, will launch in 2004 on a mission to comet Tempel 1. The spacecraft will fire a 500 kg copper projectile into the comet's nucleus on July 4, 2005. The projectile, traveling at 10 kilometers per second, will excavate ices hidden deep within the comet. Instruments on the spacecraft as well as ground-based observers will study these materials to better understand the composition of the comet. (Adapted from a SpaceViews story) |
SpaceViews, Space Daily, CNN, BBC, ABC coverage. MESSENGER Homepage. Deep Impact Homepage, U. of MD and JPL News Releases. "The Science of Deep Impact" (the space project got its name before the movie came out, though). |
3rd man on the Moon dies in motorcycle accidentFormer astronaut Charles "Pete" Conrad, the third human on the Moon, has died in a motorcycle accident in southern California on July 8. He was 69. Conrad first flew in space in 1965 as pilot of Gemini 5. He went on to command Gemini 11, the next-to-last flight of the program, a year later. Conrad was probably best known as commander of Apollo 12, the second lunar landing mission. He stayed in the astronaut corps after the Apollo 12 mission and was assigned as commander of Skylab 2, the first manned mission to America's first space station.Conrad retired from NASA and the Navy after Skylab 2 and later joined McDonnell Douglas, where he worked for 20 years. During his time there he was involved with the Delta Clipper Experimental (DC-X) project, including remotely flying the small prototype for a single-stage to orbit launch vehicle from the ground. Conrad was "always pushing the boundaries, always coming into my office with a new idea and, at 69, he had the spirit of a 13-year-old," says NASA administrator Dan Goldin. (Adapted from the SpaceViews and CNN obituaries) |
Pete Conrad Memorial site and Florida Today special pages. Biographical data. SpaceViews article, CNN, again CNN, BBC, ABC coverage. Discovery Channel "BlastOff", Astronaut Hall of Fame, NASA History. DC-X. |
Russian Proton crash raises new questionsA Russian Proton rocket crashed to Earth minutes after launch from Kazakhstan on July 5th. The Proton-K had lifted off at 13:32 UTC from Baikonur, Kazakhstan, carrying a Raduga communications satellite for the Russian military. The launch apparently proceeded well for the first several minutes, but shortly thereafter telemetry from the rocket was lost. It seems that the second stage of the Proton failed to separate after its engines shut down, and the third stage engines failed to start.Unable to reach orbit, the Proton crashed to Earth more than 1000 km from the launch site - where later traces of toxic fuel were found. The failure of the Proton launch is the first in several years for the Proton itself. The investigation into the Proton failure could have an impact on future Proton flights, including the November launch of the Zvezda service module for ISS. (Based on SpaceViews of July 6 and other sources) |
News coverage from SpaceViews, Astronomy Now. As a consequence of the accident Kasachstan has banned satellite launches from Baikonur: BBC, SpaceViews coverage. And this in turn threatens the Mir crew as no new supplies can be launched: ABC, CNN. An air leak on Mir is not serious, however: BBC, SpaceViews. |
NASA confirms: Chandra is go for the 20th!NASA managers set Tuesday, July 20, 1999, as the official launch date for the 2nd Space Shuttle Mission of the year that will mark the launch of the first female Shuttle Commander and the Chandra X-Ray Observatory. Columbia is scheduled to liftoff from Launch Pad 39-B at the opening of a 46-minute launch window at 4:36 a.m. UTC. The five-day mission is scheduled to end with a night landing at KSC just after 3:30 a.m. UTC on July 25. Following its deployment from the Shuttle, Chandra will join the HST and the CGRO as the next in NASA's series of "Great Observatories." Chandra will spend at least five years in a highly elliptical orbit which will carry it one-third of the way to the moon to observe invisible and often violent realms of the cosmos. |
NASA announcement of flight date. Countdown for STS-93. Chandra Homepage. NASA Science interview on Chandra. CNN on the first female commander. |
Major bolide shakes New ZealandA sonic boom created by a great bolide passing over New Zealand's North Island was strong enough to set off seismographs that monitor volcanic activity. The extremely bright meteor was seen from various locations throughout the country late on July 7th local time: According to early reports it had a heavy smoke trail, broke off pieces at several points across the flight path, was extremely bright, but not as bright as the sun, its color varied from orange/yellow to blue/white, and it caused tremendous sounds, from explosions, and sonic booms. "It was just like a bomb gone off and just underneath the explosion there was this falling object like in a leaf fashion falling down with smoke coming from it," one eyewitness described the event. (Based on postings in the meteorobs mailing list and CNN) |
A CNN story and news collections from July 8th and 9th. And a Diary of a Fireball - how not to do science... Somewhat related stories: "Deep Impact" in Chesapeake Bay: About 35 Myr ago a huge rock or chunk of ice slammed into the Atlantic Ocean - USGS Press Release, Explore Zone story. Did Asteroids and Comets Turn the Tides of Civilization? A non-conventional view of human history by a "neo-catastrophist" has appeared in Discovering Archaeology. And here are more speculations and an opposing view. |
Why cosmologists are worried these daysIt had been hailed as the 'Breakthrough of the Year' 1998 and a major step ahead in observational cosmology: the discovery that distant Type Ia supernovae are "too faint", indicating an accelerating expansion of the Universe (Updates # 68 and 115). The consequences would be far-reaching for astronomy and physics alike, and thus an aggressive search for hidden systematic errors in the complex supernova work was needed. Now the first possible show-stoppers have been found - but whether anyone of them will topple last years 'breaktrough' remains to be seen.
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Is there an evolution in the SN Ia phenomenon over time? Riess & al. find a "strong correlation between the risetime (i.e., the time between explosion and maximum), the post-rise light-curve shape,and the peak luminosity. [...] SNe Ia which are 0.10 mag brighter at peak in the B-band require 0.80+/-0.05 days longer to reach maximum light." And Riess & al. (other al.'s) find that the "fiducial risetime of the nearby SNe Ia is 2.5+/-0.4 days longer" than at high redshift: This "indicates possible evolution between the samples of SNe Ia", although "we cannot directly determine the impact of the apparent evolution on previous determinations of cosmological parameters." Cosmological Constant or Intergalactic Dust? Constraints from the Cosmic Far Infrared Background are discussed by Aguirre & Haiman: "IG dust probably could not reconcile the standard Omega=1 CDM model with the SN observations, even if the necessary quantity of dust existed." No Hubble Bubble in the Local Universe find Giovanell & al.: "We have combined the peculiar velocity data of two samples of clusters of galaxies [...] to investigate the amplitude of Hubble distortions to 200/h Mpc. [...] Our results are [...] consistent with a Hubble flow that, on distances in excess of about 50/h Mpc, is remarkably smooth." How little we know about type Ia SNe and the mechanism of their explosion was discussed recently by Livio. And one wonders how much of a nice review of modern cosmology by Bahcall & al. will stand the test of time... |
Bright spots near Supernova 1987A challenge explosion models: relativistic jets involved?It happened over 12 years ago but re-analysed speckle-interferometric data from the famous supernova 1987A in the Large Magellanic Cloud are only now hinting at something really strange. Already in 1987 some scientists had claimed to see a transient "mystery spot" close to the exploded star, others disputed its existence. And now not only the spot is clearly identified in the data but also a second, fainter spot on the other side of the supernova! And it seemed to to run away from the star faster than the speed of light: Such an (apparent) "superluminal motion" is the well-known signature of an relativistic jet pointing in our direction. This, plus the symmetry of the situation, indicates that the explosion of the star was an extremely non-spherical process in which matter was shot away near the speed of light in two opposing directions. Those who look for a unified model of supernovae and gamma ray bursts (see e.g. Update # 84, an otherwise rather unpopular idea) will take notice. (Nisenson & Papaliolios, Ap.J. 518 [June 10, 1999] L29-32) |
The Paper by Nisenson & Papaliolios. Changes in the ring around the SN remnant began some time ago and should shed more light onto the physics of the explosion. Wang & Wheeler on "The Supernova-Gamma Ray Burst Connection", a highly controversial paper... |
The solar wind 'surfs' waves in the coronaWorking on data first gathered from the ESA's SOHO and then by NASA's Spartan 201 spacecraft (that last flew in 1998; see Update # 109), researchers have found that the solar wind streams out of the Sun by "surfing" waves in the Sun's atmosphere. These waves are formed by rapidly vibrating magnetic fields in the coronal plasma. They are called magneto - hydro - dynamic (MHD) waves and are believed to accelerate the solar wind. The observations have made it abundantly clear that heavy particles like oxygen 'surf' on the waves, and there is also mounting evidence that waves are responsible for accelerating the hydrogen atoms, the most common constituent of the solar wind. Future observations are needed to establish this fact. (Cranmer & al., Ap.J. 518 [June 20, 1999] 937-47 etc.) |
ESA Science News. NASA Science News. SOHO Instruments, SPARTAN Homepages. |
Sahara's abrupt desertification started by changes in Earth's orbitThe desertification of North Africa began abruptly 5440 years ago (+/- 30 years): Before that time, the Sahara was covered by annual grasses and low shrubs. The transition to today's arid climate occurred in two specific episodes. The first, which was less severe, occurred between 6700 and 5500 years ago. The second, which was brutal, lasted from 4000 to 3600 years ago. Summer temperatures increased sharply, and precipitation decreased. This event devastated ancient civilizations and their socio-economic systems.The change from the mid-Holocene climate to that of today was initiated by changes in the Earth's orbit and the tilt of Earth's axis. Some 9000 years ago, Earth's tilt was 24.14 degrees, as compared with the current 23.45 degrees, and perihelion, the point in the Earth's orbit that is closest to the Sun, occurred at the end of July, as compared with early January now. The changes in Earth's orbit occurred gradually, however, whereas the evolution of North Africa's climate and vegetation were abrupt. A new study now shows that various feedback mechanisms within Earth's climate system amplified and modified the effects touched off by the orbital changes. (Claussen & al., Geophys. Res. Lett. 26 [July 15, 1999] 2037-40) |
AGU News Release The complete paper! The institute of the discoverers in Potsdam, Germany. News coverage from the BBC. |
German Space Agency confirms ABRIXAS lossIn a statement from July 5th DLR has confirmed the report from the last issue: The solar batteries of the damaged satellite didn't receive enough sunlight. There will be more attempts to talk to the s/c, but the astronomy mission is over - and the astronomers involved blame the disaster on a design error of the battery system that inevitably overheated and died. Also a German wire report.The most distant Methane Brown Dwarfhas been discovered with ESO telescopes about 100 pc away: a paper by Cuby & al.. The earlier discoveries of isolated Methane Dwarfs (see Update # 133) are discussed by Strauss & al. (SDSS) and Burgasser & al. (2MASS).Supernova particles in ocean sedimentshave been identified by their radioactive signature: Science News article and a BBC story.Wanna see an eclipse at sunset or sunrise?O. Staiger has calculated some simulated views for various eclipses in 2000 ... 2003.Three major space anniversaries
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New AstroAlert service!Get instant e-mail notice when something happens in the sky with S&T's AstroAlert Service! It will further increase amateur contributions to science.The sharpest image of the "Cydonia City"near the former 'Face on Mars' was obtained by the MGS on June 27th.MGS' MOLA observes the Polar Lander landing site - colorful DTM maps are available. And there's a recent review of MGS achievements. An extremely luminous galaxy at z=5.74has been discovered during a survey with the Keck II telescope: It's enormously bright Lyman-Alpha emission (that led to its discovery) tranlates into a star formation rate of 7...40 solar masses per year - a paper by Hu et al..Mystery payload: What did the NRO launch on the latest Titan?The Titan IV that launched a secret payload on May 22nd (see Update # 132, small items) delivered it into a most unusual orbit (2695 x 3300 km) - and left 9 secondary objects that are as mysterious as the main payload. (AW&ST of July 5th, 1999, p. 17)
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Compiled and written by Daniel Fischer
