Mars Then and Now

Mars Then and Now



Does Mars have canals? A hot debate topic of the late 1800s, several prominent astronomers including Percival Lowell not only claimed to see an extensive system of long straight canals on Mars, but used them to indicate that intelligent life exists there. The relatively close opposition of 1894 was used to make drawings like the one digitally re-scaled on the above left. The above map was originally prepared by Eugene Antoniadi and redrawnby Lowell Hess for the book Exploring Mars, by Roy A. Gallant.In more modern times, the latest Mars opposition has allowed the Hubble Space Telescope to capture a picture of similar orientation. Comparison of the two images shows that large features were impressively recorded, but that an extensive system of long and straight canals just does not exist. Satellites orbiting Mars have now shown conclusively that the red planet does indeed have surface features similar to canals, but that these are usually smaller, curved, and less extensive than that previously claimed. Real canyon systems like Noctis Labyrinthus are most likely cracks caused by surface stress.

Eclipsed Moonlight from Connelly s Springs

Eclipsed Moonlight from Connelly s Springs



Happily, skiesover Connelly's Springs, North Carolina, USAwere not mostly cloudy, as forecast, on the evening of November 8.In fact they were mostly clear early on, allowing photographerDavid Cortner to record the evening' scheduledcelestial entertainment, total lunar eclipse.Cortner took telescopic pictures of the Moon everyeight minutes as it entered partial eclipsearound 6:30pm EST and progressed throughthe reddis totaleclipse phase while rising higher in the sky.Near the end of the eclipse he also recorded a wide-angle viewin a long exposure, bringing out thethickening clouds and a landscape silhouetted by still partiall eclipsed moonlight.Later, the telescopic views were carefully combined along th Moon's trail through thewide-angle image to creat this dramatic compositeeclipse sequence.

An Intermediate Polar Binary System

An Intermediate Polar Binary System



How can two stars create such a strange and intricate structure? Most stars are members of multiple-star systems. Some stars are members of close binary systems where material from one star swirls around the other in an accretion disk. Only a handful of stars, however, are members of an intermediate polar, a system featuring a white dwarf star with a magnetic field that significantly pushes out the inner accretion disk, only allowing material to fall down its magnetic poles. Shown above is an artist's depiction of an intermediate polar system, also known as a DQ Hercules system. The foreground white dwarf is so close to the normal star that it strips away its outer atmosphere. As the white dwarf spins, the columns of infalling gas rotate with it. The name intermediate polar derives from observations of emitted light polarized at a level intermediate to non-disk binary systems known as polars. Intermediate polars are a type of cataclysmic variable star system.

Apollo 17 Lunarscape A Magnificent Desolation

Apollo 17 Lunarscape A Magnificent Desolation



Buzz Aldrin, Apollo 11 Lunar Module pilot and th second human to walk onthe Moon, described the lunar landscape as "a magnificent desolation".Dramatic pictures fromthe Apollo missionsto the lunar surfacetestify to this apt turn of phrase.Near the Apollo 17 landing site,Family Mountain (center background) and the edge of South Massif (left) fram the lunarscape in this photo o astronaut Harrison Schmittworking alongsid the lunar roving vehicle.Schmitt and fello astronaut Eugene Cernan were th lastto walk on this magnificent desolation.

Eclipsed Moon in Infrared

Eclipsed Moon in Infrared



The total lunar eclipse of September 1996disappointed many observers in North America whowere cursed with cloudy skies.However, th MidcourseSpace Experiment (MSX) satellite hada spectacular view from Earth orbit an SPIRIT III,an on board infrared telescope, was used torepeatedly image the moo during the eclipse.Above is one ofthe images taken during the 70 minute totality, the Moon completel immersed inthe Earth's shadow.Infrared ligh has wavelengthslonger than visible light - humans can not see it but feel it as heat.The bright spots correspond to the warm areas on thelunar surface, dark areas are cooler.The brightest spot below and left of center is th crater Tycho,the dark region at the upper right i the Mare Crisium.The series of SPIRIT III images allow the determination of coolingrates for geologically different areas, exploring the physical propertie of the Moon's surface.

November's Lunar Eclipse

November's Lunar Eclipse



The Moon slides through the Earth's shadowthis Saturday night / Sunday morning (November 8/9) givingskygazers in the Americas, Europe,Africa, and western Asia a chance t enjoy a total lunar eclipse.A lunar eclipses go,this will be a brief onethough, with the total phase lasting only about 25 minutes.The orientation and relative size of th Earth's shadowand the Moon's trajectory are illustrated in this thoughtfulanimation showing the full Moon moving up from the lower right,entering the penumbra or outer portion of the shadow region,and then passing well below the center of the darker inner shadow regionor umbra.The tota eclipse phase beginsat 1:06 Universal Time, November 9(8:06pm EST Nov. 8 whenthe Moon is completely within the umbra.While the off-center passage guarantees a short total phase, italso makes it likely that this November's eclipsed Moon will bedramatically visible and colorfulwith a brighter rim along thesouthern edge.

Flare Well AR 10486

Flare Well AR 10486



Almost out of view fro our fair planet,rotating around theSun's western edge, giant sunspot regio AR 10486lashed outwith another intense solar flare followed bya larg coronalmass ejection (CME) on Tuesday, November 4that about 1950 Universal Time.The flare itself is seen here at the lower right in an extremeultraviolet image from th sun-staring SOHO spacecraft's EITcamera.Saturating the EIT camera pixels and detectors onother satellites, this giant X-classflare was among themost powerful ever recorde sincethe 1970s, the third such historicblast from AR 10486 within the last two weeks.While energetic particle radiation from the flare did causesubstantial radio interference, the associated CME is notexpected to trigger extremely widespread aurorae as it glances offthe magnetosphere, unlike th direct hits from last week's CMEs.Say farewell to the mighty AR 10486, for now.For the next two weeks, the sunspot region will be on the Sun' far side.

The Lynx Arc

The Lynx Arc



While chasing the spectrum of a mysterious arc in a cluster ofgalaxies within the obscure northerl constellationLynx, astronomers havestumbled upon the most massive and distant star-forming regio ever discovered.The notably red "Lynx arc" lies right of center i thiscolor image of the galaxy cluster, a composite ofHubble Space Telescope and ground-based data.While the galaxy cluster lies about 5 billionlight-years distant spectroscopic studiesshow that the arc itself is actually a distortedimage of an even more distant but enormous star-forming region.The image is formed as the closer galaxy cluster' gravitybends lightlike a magnifying lens, an effect explained by Einstein'stheory of gravity In fact, the monster star-forming region is nearly12 billio light-years awayand about a million times brighter than themore familiar stellar nursery, th Orion Nebula.Estimates are that the star-forming region seen as theLynx arc contains about a million massive, hot stars, comparedto the four stars which power theOrion Nebula's glow. Stars within the Lynx arc are more than twice as hotas the Orion Nebula's central starsand were formed whenthe Universe was a mere 2 billion years old.Still, astronomers believe that th first stars wereformed at even earlier times.

Aurora Over Edmonton

Aurora Over Edmonton



Northern and southern locales saw many a beautiful aurora over the last week, as particles from severa large solar flares impacted the Earth. Many reported unusually red auroras, although colors across the spectrum were also seen. Power grids and orbiting satellites braced for the onslaught, but little lasting damage was reported. Pictured above, the Clover Bar Power Plant was photographed from the banks of the North Saskatchewan River in Edmonton, Alberta Canada. A small pond in the foreground reflects predominantly green aurora light far in the distance. Two days ago, again unexpectedly, another large solar flare occurred from sunspot group 10486, the site ofother recent major flares. This unusually active solar region is now rotating to the far side of the Sun.

Spiral Galaxy NGC 3982 Before Supernova

Spiral Galaxy NGC 3982 Before Supernova



What do stars look like just before they explode? To find out, astronomers are taking detailed images of nearby galaxies now, before any supernova is visible. Hopefully, a star in one of the hundreds of high resolution galaxy images will explode in the coming years. If so, archival images like that taken above by the Hubble Space Telescope can be inspected to find what the star looked like originally. This information is likely important for better understanding of how and why supernovas occur, as well as why some supernovas appear brighter than others. Pictured above, beautiful spiral galaxy NGC 3982 displays numerous spiral arms filled with bright stars, blue star clusters, and dark dust lanes. NGC 3982, which spans about 30,000 light years, lies about 60 million light years from Earth and can be seen with a small telescope toward the constellation of Ursa Major.