Uranus is the only giant planet whose equator is nearly at right angles to its orbit. A collision with an Earth-sized object may explain Uranus’ unique tilt. Nearly a twin in size to Neptune, Uranus has more methane in its mainly hydrogen and helium atmosphere than Jupiter or Saturn. Methane gives Uranus its blue tint.
Featured Mission: Voyager 2 Most of what we know about Uranus came from Voyager 2’s flyby in 1986. The spacecraft discovered 10 additional moons and several rings before heading on to Neptune.
This pulsar lies near the center of the Vela supernova remnant, which is the debris of the explosion of a massive star about 10,000 years ago. The pulsar is the collapsed core of this star, rotating with a period of 89 milliseconds or about 11 times a second. Radiation is beamed out along the magnetic poles and pulses of radiation are received as the beam crosses the Earth, in the same manner as the beam from a lighthouse causes flashes. Being enormous cosmic flywheels with a tick attached, they make some of the best clocks known to mankind. These sounds directly correspond to the radio-waves emitted by the brightest pulsars in the sky as received by some of the largest radio telescopes in the world.
The amazing image above of a sunset on exo-planet HD209458b 150 light years away, was reconstructed by Frederic Pont of the University of Exeter using data from a camera onboard theHubble Space Telescope. Pont used his knowledge of how the color of light changes based on chemicals it encounters, and computer modeling, to create an actual image of what a sunset on the actual planet would look like.
The large exo planet in question, exoplanet HD209458b, nicknamed Osiris, circles its star rather closely. At certain points, when the planet passes between us and its star, the light from that star passes through Osiris’s atmosphere before reaching us, which allowed Pont to determine the chemical composition of the atmosphere and deduce what colors would appear to the naked human eye.
The light from Osiris’s star is white, like our own sun, but when it passes through the sodium in Osirisi’s atmosphere, red light in it is absorbed, leaving the starlight to appear blue. But as the sun sets, the blue light is scattered in the same way as it is here on Earth (Rayleigh scattering) causing a gradual change to green, and then to a dim dark green. And finally, due to diffraction, the bottom of the image becomes slightly flattened. [x]