This image of Mercury, acquired by the Mercury Dual Imaging System (MDIS) aboard NASA’s MESSENGER mission on April 23, 2013, allows us to take a step back to view the planet. Prior to the MESSENGER mission, Mercury’s surface was often compared to the surface of Earth’s moon, when in fact, Mercury and the moon are very different. This image in particular highlights many basins near Mercury’s terminator, including Bach crater. Many craters with central peaks and the nearby bright rays of Han Kan crater are also evident.
Once per week, MDIS captures images of Mercury’s limb, with an emphasis on imaging the southern hemisphere limb. These limb images provide information about Mercury’s shape and complement measurements of topography made by the Mercury Laser Altimeter (MLA) of Mercury’s northern hemisphere.
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Two or three times a year, NASA’s Solar Dynamics Observatory observes the moon traveling across the sun, blocking its view. While this obscures solar observations for a short while, it offers the chance for an interesting view of the shadow of the moon. The moon’s crisp horizon can be seen up against the sun, because the moon does not have an atmosphere. (At other times of the year, when Earth blocks SDO’s view, the Earth’s horizon looks fuzzy due to its atmosphere.)
If one looks closely at such a crisp border, the features of the moon’s topography are visible, as is the case in this image from Oct. 7, 2010. This recently inspired two NASA visualizers to overlay a 3-dimensional model of the moon based on data from NASA’s Lunar Reconnaissance Orbiter, or LRO, into the shadow of the SDO image. Such a task is fairly tricky, as the visualizers — Scott Wiessinger who typically works with the SDO imagery and Ernie Wright who works with the LRO imagery — had to precisely match up data from the correct time and viewpoint for the two separate instruments. The end result is an awe-inspiring image of the sun and the moon.
Image Credit: NASA/SDO/LRO/GSFC
The bright clusters and nebulae of planet Earth’s night sky are often named for flowers or insects. Though its wingspan covers over 3 light-years, NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the dying central star of this particular planetary nebula has become exceptionally hot, shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust.
This sharp and colorful close-up of the dying star’s nebula was recorded in 2009 by the Hubble Space Telescope’s Wide Field Camera 3, installed during the final shuttle servicing mission. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is near the center of this view, almost edge-on to the line-of-sight. Molecular hydrogen has been detected in the hot star’s dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation of the Scorpion (Scorpius).
Image Credit: NASA/ESA/Hubble
This image from the NASA/ESA Hubble Space Telescope captures an ongoing cosmic collision between two galaxies — a spiral galaxy is in the process of colliding with a lenticular galaxy.
The image also reveals further evidence of the collision. There is a bright stream of stars coming out from the merging galaxies, extending out towards the top of the image. The bright spot in the middle of the plume, known as ESO 576-69, is what makes this image unique. This spot is believed to be the nucleus of the former spiral galaxy, which was ejected from the system during the collision and is now being shredded by tidal forces to produce the visible stellar stream.
Image Credit: European Space Agency/NASA Hubble
Like a proud peacock displaying its tail, Enceladus shows off its beautiful plume to the Cassini spacecraft’s cameras.
Enceladus (313 miles, or 504 kilometers across) is seen here illuminated by light reflected off Saturn.
This view looks toward the Saturn-facing side of Enceladus. North on Enceladus is up and rotated 45 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 18, 2013.
The view was acquired at a distance of approximately 483,000 miles (777,000 kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 173 degrees. Image scale is 3 miles (5 kilometers) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
Credit: NASA/JPL-Caltech/Space Science Institute
An Extraordinary Celestial Spiral (via placidiappunti)
Credit:ESA/NASA & R. Sahai
The spinning vortex of Saturn’s north polar storm resembles a deep red rose of giant proportions surrounded by green foliage in this false-color image from NASA’s Cassini spacecraft. Measurements have sized the eye at a staggering 1,250 miles (2,000 kilometers) across with cloud speeds as fast as 330 miles per hour (150 meters per second).
This image is among the first sunlit views of Saturn’s north pole captured by Cassini’s imaging cameras. When the spacecraft arrived in the Saturnian system in 2004, it was northern winter and the north pole was in darkness. Saturn’s north pole was last imaged under sunlight by NASA’s Voyager 2 in 1981; however, the observation geometry did not allow for detailed views of the poles. Consequently, it is not known how long this newly discovered north-polar hurricane has been active.
The images were taken with the Cassini spacecraft narrow-angle camera on Nov. 27, 2012, using a combination of spectral filters sensitive to wavelengths of near-infrared light. The images filtered at 890 nanometers are projected as blue. The images filtered at 728 nanometers are projected as green, and images filtered at 752 nanometers are projected as red. In this scheme, red indicates low clouds and green indicates high ones.
The view was acquired at a distance of approximately 261,000 miles (419,000 kilometers) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 94 degrees. Image scale is 1 mile (2 kilometers) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
Image Credit: NASA/JPL-Caltech/SSI
The soft glow in this image is NGC 2768, an elliptical galaxy located in the northern constellation of Ursa Major (The Great Bear). NGC 2768 appears here as a bright oval on the sky, surrounded by a wide, fuzzy cloud of material.
This image, taken by the NASA/ESA Hubble Space Telescope, shows the dusty structure encircling the center of the galaxy, forming a knotted ring around the galaxy’s brightly glowing middle. Interestingly, this ring lies perpendicular to the plane of NGC 2768 itself, stretching up and out of the galaxy.
The dust in NGC 2768 forms an intricate network of knots and filaments. In the center of the galaxy are two tiny, S-shaped symmetric jets. These two flows of material travel outwards from the galactic center along curved paths, and are masked by the tangle of dark dust lanes that spans the body of the galaxy.
These jets are a sign of a very active center. NGC 2768 is an example of a Seyfert galaxy, an object with a supermassive black hole at its center. This speeds up and sucks in gas from the nearby space, creating a stream of material swirling inwards towards the black hole known as an accretion disk. This disk throws off material in very energetic outbursts, creating structures like the jets seen in the image above.
Image Credit: NASA/ESA/Hubble