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Astronomers using NASA's Spitzer Space Telescope have greatly improved the cosmic distance ladder used to measure the expansion rate of the universe, as well as its size and age. The cosmic distance ladder, symbolically shown here in this artist's concept, is a series of stars and other objects within galaxies that have known distances.

Close-up of olivine crystals seen inside a meteorite found on Earth that originated from a partly melted Solar System asteroid. The yellow olivine crystals are on the order of a few millimetres to centimetres in size and are held together by an alloy of iron and nickel. In contrast, the olivine crystals found in pristine comets, such as in the material measured in the Beta Pictoris system by ESA’s Herschel space observatory, are iron-poor but magnesium-rich.

A dying star is throwing a cosmic tantrum in this combined image from NASA's Spitzer Space Telescope and the Galaxy Evolution Explorer (GALEX), which NASA has lent to the California Institute of Technology in Pasadena. In death, the star's dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.

Photosystem-I (green) is optically excited by an electrode (on top). An electron then is transferred step by step in only 16 nanoseconds.

This UAVSAR interferogram shows active volcano Mount St. Helens (left) and dormant volcano Mount Adams, both in Washington state. The sensor collected data for this image during flights in July 2009 and August 2010 to compute the surface deformation that could indicate activity in the volcanoes' magma. No deformation was evident during this period.

This image of the Venus southern hemisphere illustrates the terminator – the transitional region between the dayside (left) and nightside of the planet (right). The south pole is near the terminator, just above the centre of the image. The complex atmosphere that surrounds the planet is also clearly visible.

Following bombardment with highly charged ions, nano-hillocks have formed in an area of localized melting. Atomic force microscope image.

Rock fins up to about 1 foot (30 centimeters) tall dominate this scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity.

A three-dimensional image of an etched gallium-arsenide semiconductor, taken during etching with a new microscopy technique that monitors the etching process on the nanometer scale. The height difference between the orange and purple regions is approximately 250 nanometers.