Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; dozens of moons; and millions of asteroids, comets, and meteoroids.

Observations show that the same elements exist throughout the known universe. We organize information about the elements in the form of a periodic table.

While Earth is only the fifth largest planet in the solar system, it is the only world in our solar system with liquid water on the surface. Just slightly larger than nearby Venus, Earth is the biggest of the four planets closest to the Sun, all of which are made of rock and metal.

If matter is distributed homogeneously—smoothly and uniformly—throughout the universe on a cosmic scale, then universe expansion is the only important large-scale motion and its rate might be measured more easily.

Specially designed Cassini orbits placed Earth and Cassini on opposite sides of Saturn's rings, a geometry known as occultation. Cassini conducted the first radio occultation observation of Saturn's rings on May 3, 2005.

The determination of the density of the universe is a very difficult problem. What is its mass? What is the volume of the universe? Clearly these values cannot be determined directly and astronomers are forced to make approximations, guesses, and simplifications. GRAVITY

view the Earth, ourselves, and the universe in a new way. While the tremendous technical and scientific accomplishments of NASA demonstrate vividly that humans can achieve previously inconceivable feats, we also are humbled by the realization that Earth is just a tiny 'blue marble' in the cosmos." Timelines are an effective way to understand the

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She is the recipient of the National Science Foundation's Graduate Research Fellowship, which provides 3 years of funding for her to pursue research about how galaxies evolve over the age of the Universe.

N00219275.jpg was taken on 2014-01-03 13:34 (PST) and received on Earth 2014-01-04 06:23 (PST). The camera was pointing toward Daphnis, and the image was taken using the CL1 and CL2 filters. This image has not been validated or calibrated. A validated/calibrated image will be archived with the NASA Planetary Data System