The Shuttle Radar Topography Mission used interferometry by flying two separate radar antennas placed 60 meters, or 200 feet, apart! Elsewhere on The Space Place, we talk about interferometry as it will be used in ground telescopes. The beautiful colors were put in later to make the details easier to see.īut what is really new and special about the Shuttle Radar Topography Mission is that it combines imaging radar with another wonderful technology called interferometry. For example, this picture of the mountains in Tibet was made by an imaging radar mission called SIR-C/X-SAR. We have flown imaging radar missions before and made radar images of different parts of the world. Imaging radar uses a different kind of light, but at a much longer, lazier wavelength that our eyes do not see. And imaging radar can see all this day or night, cloudy or clear. From this information, we can make very accurate pictures of the surface, its bumps (like mountains, hills, and valleys), its textures (like forests, lakes, and cities), and its changing moods (like volcanos, floods, and earthquakes). Imaging radar bounces a radar signal off the ground, then measures how long the signal takes to come back and how strong it is. It used a technology called imaging radar. The Shuttle Radar Topography Mission flew on the Space Shuttle Endeavour in February 2000. From this information, we can make very accurate pictures of the surface. Titanic mergers between galaxies or interstellar winds from catastrophic supernovas can also have smashed clouds together into stars, she explained.Imaging radar bounces a radar signal off the ground, then measures how long the signal takes to come back and how strong it is. Giant clouds of interstellar gas can fragment under their own gravity, collapsing into star-forming pockets. Stars might have formed in bursts due to a variety of triggers, Skowron said. "We can see with our own eyes and within our own galaxy that star formation is not constant but indeed is happening in bursts." "This is a clear indication that they were created together," Skowron said. They found clusters of Cepheids with very similar ages. "It is apparent by eye."Īstronomers can deduce the age of Cepheids based on their patterns of pulsations. "It is not some statistical fact available only to a scientist's understanding," she said. The amount of warping the researchers saw in the Milky Way was surprisingly pronounced, Skowron said. "Warping of the galactic disk has been detected before, but this is the first time we can use individual objects to trace its shape in three dimensions," study co-author Przemek Mróz at the University of Warsaw said in a statement. This warping was potentially caused by the galaxy's interactions with satellite galaxies, intergalactic gas or dark matter. Specifically, the galaxy's disk is not flat at distances greater than 25,000 light-years from the galactic core, but warped. The new map helped reveal more details on distortions that astronomers had previously detected in the shape of the Milky Way. ![]() ![]() This is the first such map based on directly measured distances to thousands of celestial landmarks across the galaxy. These findings helped the astronomers build a large-scale 3D map of the Milky Way. "This took six years but it was worth it," study lead author Dorota Skowron, an astrophysicist at the University of Warsaw in Poland, told. Using the Optical Gravitational Lensing Experiment, which monitors the brightness of nearly 2 billion stars, the scientists charted the distance between the sun and more than 2,400 Cepheids throughout the Milky Way. Skowron/OGLE/Astronomical Observatory, University of Warsaw) Red points indicate older stars, while younger ones are shown in blue. This image compares a simulation of the Milky Way galaxy's Cepheid star variables (left) with actual observations of their numbers (right).
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