SOHO spacecraft spots comet 96P, a return visitor
Comet 96P has returned. The comet as spotted by the Solar and Heliospheric Observatory (SOHO) satellite, a joint mission operated by NASA and the European Space Agency.
As revealed in a blog post published by NASA, the comet moved into view of SOHO on Oct. 25 and exited frame on Oct. 30, UPI reported.
SOHO was launched in 1996, and though its main task is to study the Sun, it’s found time over the last two decades to discover some 3,000 comets. Of all those comets, only some are recurring visitors, and 96P is the most frequent guest, having previously made appearances in 1996, 2002, 2007 and 2012.
Comet 96P/machholz was originally spotted on May 12, 1986, by Donald Machholz, an amateur astronomer.
Machholz spied the short-period sungrazing comet from Central California’s Loma Prieta using only binoculars.
Amazingly, comet 96P’s latest perihelion, the portion of its orbit nearest to the Sun, was also spotted by another spacecraft, NASA’S Solar and Terrestrial Relations Observatory, or STEREO.
The comet completes an orbit every 5.24 years and travels within a uniquely close 11 million miles of the sun during its perihelion.
Astronomers hope to combine the data collected by SOHO and STEREO to discern new details about the comet’s composition and study how the icy body reacted with highenergy particles streaming from the sun as it rounded the fiery orb.
Both spacecraft were able to observe polarized light coming from the comet’s tail.
As a light wave passes through a medium, like a comet’s tail, its spin becomes oriented in a uniform direction.
The polarization can reveal details about the molecules in the medium through which the lightwave passed.
William Thompson, NASA scientist and STEREO chief observer at Goddard Space Flight Center, said, “Polarization is a strong function of the viewing geometry, and getting multiple measurements at the same time could potentially give useful information about the composition and size distribution of the tail particles.
The last time astronomers observed comet 96P, they found two fragments leading the main body, suggesting the comet was breaking apart and evolving. A third fragment was spotted on its latest pass.
As larger comets break apart, they form newer comets with related compositions. These lineages are organized into families.
Researchers believe comet 96P has fathered two comet families, each with unique compositions.
The fragments of some of 96P’s offspring collide with Earth’s atmosphere, producing meteor showers. Scientists hope further study the 96P will help them better understand how comets evolve and spawn families. NASA’S next Mars rover will be the sharpest-eyed craft ever to touch down on the Red Planet.
The 2020 Mars rover — which, as its name suggested, is scheduled to launch in 2020 — will feature a total of 23 cameras, NASA officials said, according to foxnews. com.
That’s six more than NASA’S Curiosity rover, which has been exploring Mars’ Gale Crater since August 2012, and 13 more than the golf-cart-size twin rovers Spirit and Opportunity, which touched down in different regions of the Red Planet a few weeks apart in January 2004.
Mars 2020 imaging scientist Justin Maki, of NASA’S Jet Propulsion Laboratory (JPL) in Pasadena, California, said, “Camera technology keeps improving.
“Each successive mission is able to utilize these improvements, with better performance and lower cost.”
Mastcam-z, an upgraded version of Curiosity’s highdefinition, two-camera Mastcam instrument, will serve as Mars 2020’s main set of eyes on the Red Planet.
The ‘Z’ is for zoom, a capability that Curiosity’s Mastcam does not have. (‘Mastcam’, meanwhile, refers to the fact that the to examine geologic features in more detail and scout out promising scientific sites from large distances, NASA officials said.
Mastcam-z principal investigator Jim Bell, of Arizona State University in Tempe, said, “Routinely
Seven of the Mars 2020 cameras are part of scientific packages. Another seven will take pictures during the rover’s entry, descent and landing (which, like with Curiosity, will employ a rocketpowered sky crane).
The other nine are