Blue Whisps

Turquoise-tinted plumes in the Large Magellanic CloudThis Hubble image shows part of the outskirts of the Tarantula Nebula in the Large Magellanic Cloud. The colors seen in this picture are different from what we normally see in the images of the Large Magellanic Cloud  because an unusual set of filters was used. The customary R filter, which passes red light, was replaced by a filter letting through the near-infrared light. Hydrogen gas normally appears pink because it shines most brightly in the red. In this case, however, other less prominent emission lines dominate in the blue and green filters.

Image Credit: NASA

Comet Siding Spring

Siding Spring MROThese images were taken of Comet C/2013 A1 Siding Spring by the Mars Reconnaissance Orbiter on 19 October during the comet’s close flyby of Mars. The comet is on its first trip this close to the sun from the Oort Cloud at the outer fringe of the Solar System. These are the first resolved images of the nucleus of a long-period comet.

The images of the comet were acquired at a range of about 138,000 kilometers. The scale is roughly 138 meters per pixel. Telescopic observations had suggested that the size of the nucleus was about 1 km wide. However, the best Mars Reconnaissance Orbiter images are two to three pixels across the brightest feature, suggesting that the size of the nucleus is less than half the earlier estimate.

This composite image shows two versions of two of the best images take by the HiRISE camera on the Mars Reconnaissance Orbiter. At the top are images with the full dynamic range, showing the nucleus and bright coma near the nucleus. At the bottom are versions where the fainter outer coma is brightened, saturating the inner region. The left and right images were taken about nine minutes apart.

Image Credit: NASA

NGC 3310

NGC 3310NGC 3310 is a grand design spiral galaxy in the constellation Ursa Major. It is also a starburst galaxy. (Starburst galaxies are undergoing an exceptionally high rate of star formation.) NGC 3310 probably collided with one of its satellite galaxies about 100 million years ago, triggering widespread star formation. The ring clusters of NGC 3310 have been undergoing starburst activity for at least the last 40 million years.

Image Credit: NASA

Mars Orbiter and Comet Siding Spring

This afternoon, Comet C/2013 A1 (AKA Comet Siding Spring) will pass within about 140,000 km of Mars. That’s less than half the distance between Earth and the Moon and less than one-tenth the distance of any known comet flyby of Earth. Siding Spring’s nucleus will come closest to Mars around 18:27 UTC (2:27 pm ET) moving at around 56 km/s.

Video Credit: NASA


NASA’s newest sun-watcher is the Interface Region Imaging Spectrograph. It was launched last year to track how energy and heat move through a little understood region of the sun called the interface region which is sandwiched between the solar surface and its outer atmosphere or corona. The interface region is where the cooler temperatures of the sun’s surface transition to the hotter temperatures above. All the energy to power the sun’s output must make its way through this region. This movie shows succeeding images from IRIS of the same area of the sun in different wavelengths. Each image carries information about how fast the solar material is moving, which has shown scientists that a series of loops are twisting in the sun’s lower atmosphere.

Video: NASA