Earth and the International Space Station

Backdropped by a blue and white Earth, the International Space Station is seen from Space Shuttle Discovery as the two spacecraft begin their relative separation. Earlier the STS-119 and Expedition 18 crews concluded 9 days, 20 hours and 10 minutes of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 2:53 p.m. (CDT) on March 25, 2009.

Space Shuttle Discovery, Orbit of the Earth

March 25, 2009

Image Credit: NASA

Saturn and Mimas

From high above Saturn's northern hemisphere, NASA's Cassini spacecraft gazes over the planet's north pole, with its intriguing hexagon and bullseye-like central vortex.

Saturn's moon Mimas is visible as a mere speck near upper right. At 246 miles (396 kilometers across) across, Mimas is considered a medium-sized moon. It is large enough for its own gravity to have made it round, but isn't one of the really large moons in our solar system, like Titan. Even enormous Titan is tiny beside the mighty gas giant Saturn.

This view looks toward Saturn from the sunlit side of the rings, from about 27 degrees above the ring plane. The image was taken in green light with the Cassini spacecraft wide-angle camera on March 27, 2017.

The view was acquired at a distance of approximately 617,000 miles (993,000 kilometers) from Saturn. Image scale is 37 miles (59 kilometers) per pixel. Mimas' brightness has been enhanced by a factor of 3 in this image to make it easier to see.

Image Credit: NASA/JPL-Caltech/Space Science Institute
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21331

Stein 2051 B

Looks can be deceiving. In this Hubble Space Telescope image, the white dwarf star Stein 2051 B and the smaller star below it appear to be close neighbors. The stars, however, reside far away from each other. Stein 2051 B is 17 light-years from Earth; the other star is about 5,000 light-years away.

Astronomers made the Hubble observations of the white dwarf, the burned-out core of a normal star, and the faint background star over a two-year period. Hubble observed the dead star passing in front of the background star, deflecting its light. During the close alignment, the distant starlight appeared offset by about 2 milliarcseconds from its actual position. This deviation is so small that it is equivalent to observing an ant crawl across the surface of a quarter from 1,500 miles away. From this measurement, astronomers calculated that the white dwarf's mass is roughly 68 percent of the sun's mass.

Image Credit: NASA, ESA, and K. Sahu (STScI)
Explanation from: http://hubblesite.org/image/4043/news_release/2017-25