This picture was taken by the HiRISE camera on the Mars Reconnaissance Orbiter last January. It shows Mars’s northern-most sand dunes beginning to emerge from their winter cover of seasonal dry ice (frozen CO2). The dark, bare south-facing slopes are soaking up the warmth of the sun. The steep downwind sides of the dunes are also ice-free along the crest, allowing sand to slide down the dune. The dark areas are places where ice cracked earlier in the spring, releasing sand. Eventually, the dunes will be completely bare and all signs of spring activity will be gone.
This animation shows wide-angle camera images of Mercury’s south polar region taken by the MESSENGER spacecraft over one complete Mercury solar day (176 Earth days). This dataset enabled the illumination conditions at Mercury’s south polar region to be quantified, producing the map seen at the end of the movie and provided as a separate image. The map is colored on the basis of the percentage of time that a given area is sunlit; areas appearing black in the map are regions of permanent shadow. The large crater near Mercuryâs south pole, Chao Meng-Fu, has a diameter of 180 km.
The last missions that NASA had with orbits around Mars that were synched to view the morning weather on the planet was the Viking orbiters back in 1976. This picture was taken in August, 1976, and shows water-ice clouds in the Valles Marineris area of equatorial Mars during local morning time. North is to the upper left, and the scene is about 1,000 km across.
Although a few observations of Mars in morning daylight have come from the Viking orbiters and the European Space Agency’s Mars Express orbiter, no mission has systematically studied how morning features such as clouds, fogs, and surface frost develop during different Martian seasons on different parts of the planet. NASA’s Mars Odyssey orbiter is in the process of changing its orbit to begin systematic morning daylight observations.
This animation illustrates the rotation rate of the Large Magellanic Cloud (LMC). Hubble Space Telescope observations have been used to determine that the central part of the LMC completes a rotation every 250 million years. It takes more than 10 million years for even the small amount of rotation illustrated in this video.
We’re fairly certain that an asteroid impact on the Earth was the event that brought about the sudden demise of the dinosaurs. Fortunately for us, such impacts are very rare on Earth. However, they are probably more common out in the main Asteroid Belt.
This animation was generated the first mapping data of radioactivity in a supernova remnant, the blown-out bits and pieces of a massive star that exploded. The data was take by a NASA satellite called NuSTAR. The results, from a remnant named Cassiopeia A (Cas A), reveal how shock waves probably rip apart massive dying stars.
While small stars like our Sun die less violent deaths, larger stars (at least eight times as massive as the Sun) end up as supernovae. The high temperatures and particles created in explosions fuse lighter elements together to create heavier elements. The explosions of supernovae seeding the universe with many elements, including the gold in jewelry, the calcium in bones, and the iron in blood.
NuSTAR is the first telescope capable of producing maps of radioactive elements in supernova remnants—in this case, titanium-44. The NuSTAR map of Cas A shows the titanium concentrated in clumps at the remnant’s center and suggests a possible solution to the mystery of how the star met its demise. When researchers simulate supernova blasts with computers, as a massive star dies and collapses, the main shock wave often stalls out and the star fails to shatter. The latest findings strongly suggest that Cas A sloshed around, re-energizing the stalled shock wave and allowing the star to finally blow off its outer layers.
An active region of the sun just rotating into the view of the Solar Dynamics Observatory gives a profile view of coronal loops over about a two-day period, from 8 to 10 February, 2014. Coronal loops are found around sunspots and in active regions. The structures are associated with the closed magnetic field lines that connect magnetic regions on the solar surface. Some coronal loops can last for days or weeks, but most change quite rapidly. This image was taken in extreme ultraviolet light.
The Antennae Galaxies (aka NGC 4038 and NGC 4039) are a distorted pair of colliding spiral galaxies about 70 million light-years away, in the constellation of Corvus (The Crow). This false color image combines observations made in two different millimeter wavelength ranges from the European Southern Observatory’s ALMA with visible light observations from the Hubble Space Telescope.
Visible light—shown here mainly in blue—reveals the newborn stars in the galaxies, ALMA’s view shows the clouds of dense cold gas from which new stars form. The ALMA observations—shown here in red, pink and yellow—were made at specific wavelengths of millimetre and submillimetre light,tuned to detect carbon monoxide molecules in the otherwise invisible hydrogen clouds, where new stars are forming. Massive concentrations of gas are found not only in the hearts of the two galaxies but also in the chaotic region where they are colliding. The total amount of gas is billions of times the mass of the Sun, a rich reservoir of material for future generations of stars.
This is the first image of the Moon taken by a United States spacecraft. It was taken on 31 July, 1964, by Ranger 7 about 17 minutes before crashing into the surface of the moon. Mare Nubium is to the left of the center.
This rotating animation of Jupiter’s moon Ganymede begins as a global color mosaic image of the moon assembled from data from Voyager 1, Voyager 2, and the Galileo spacecraft and then fades in a newly developed geologic map.
Video Credit: USGS Astrogeology Science Ctr / Wheaton / ASU / NASA / JPL-Caltech
The Sun is always changing and the Solar Dynamics Observatory is continuously watching. SDO keeps a 24-hour eye on the entire disk of the Sun. NASA released a movie of some of SDO‘s best sightings of it’s fourth year watching the Sun, including massive solar explosions and giant sunspot shows.
SDO monitors the Sun in 10 different wavelengths, each of which highlights a different temperature of solar material. Different temperatures show specific structures on the sun such as solar flares (giant explosions of light and x-rays) or coronal loops, which are streams of solar material traveling along looping magnetic field lines. This movie shows examples of both, as well prominence eruptions, masses of solar material leaping off the Sun. The movie also shows a sunspot group on the solar surface. This sunspot, a magnetically strong and complex region appearing in mid-January 2014, was one of the largest in nine years.
In September, 2012, NASA’s FermiGamma Ray Telescope detected a series of bright gamma-ray flares from a source known as B0218+357, located 4.35 billion light-years from Earth in the direction of a constellation called Triangulum. These powerful flares in a known gravitational lens system provided the key to making the lens measurement. Long before gamma-ray bursts from B0218+357 reached us, they passed through a face-on spiral galaxy very much like our own about 4 billion light-years away. That galaxy’s gravity bent the light into different paths, so we see the background blazar as dual images. With just a third of an arcsecond (less than 0.0001 degree) between them, the B0218+357 images hold the record for the smallest separation of any lensed system known.
While radio and optical telescopes can resolve and monitor the individual blazar images, Fermi cannot. Instead, the Fermi team exploited a “delayed playback” effect. This movie illustrates the components of the gravitational lens system. Different sight lines to a background blazar resulted in two images that arrived at slightly different times. Fermi made the first gamma-ray measurements of this sort of delay in a lens system
This picture was assembled from combined observations from NASA’s Spitzer Space Telescope and ESO’s Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. It reveals the throes of stellar birth in an object known as HH 46/47.
HH or Herbig-Haro objects form when particle jets shot out by newborn stars collide with surrounding matter, producing small, bright, nebulous regions. The dynamics within many HH objects are obscured from observation with visible light by the enveloping gas and dust, but the infrared and submillimeter light seen by Spitzer and ALMA, respectively, cuts through the cloud around HH 46/47. (Infrared light has longer wavelengths than what we see with our eyes, and submillimeter wavelengths are longer still.)
In this false-color image the shorter-wavelength light appears blue and longer-wavelength light, red. Blue shows gas energized by the outflowing jets. Green traces a combination of hydrogen gas molecules and dust that follows the boundary of the gas cloud surrounding the young star. The red areas are excited carbon monoxide gas.
NASA’s Spitzer and Hubble Space Telescopes have spotted what may be one of the most distant galaxies known, from when the universe was only about 650 million years old (the Big Bang was around 13.8 billion years ago). The galaxy, known as Abell2744 Y1, was about 3 percent the size our Milky Way galaxy and was producing about 10 times more stars, as wass typical for galaxies in the young universe.
This evening I agreed to go back to work full-time for a while. I was enjoying my semi-retirement, but my former colleagues working on the GOES-R program have persuaded me to rejoin them. I’ll begin on Monday at Goddard Space Flight Center.
GOES-R is the first of the next generation of weather satellites.