Tag: Pluto
Hubble has discovered a fourth moon orbiting Pluto
Hubble has discovered a fourth moon orbiting Pluto.
Pluto’s atmosphere is expanding, and scientists don’t know why
Pluto’s atmosphere is expanding, and scientists don’t know why.
Pluto travels along a highly elliptical path and last passed closest to the sun in 1989. Many planetary scientists expected the atmosphere to shrink as the icy orb began receding from the sun’s warmth. The unanticipated expansion may be related to changes in the darkness of the orb’s surface a decade or so ago, which may have caused the surface ices to absorb more solar radiation and more efficiently evaporate. Or, Greaves suggests, long-term variations in the sun’s ultraviolet output, changes linked to the roughly 11-year cycle of solar activity, may be playing a role.
When is an Asteroid Not an Asteroid?
When is an asteroid not an asteroid?
The layered structure of Vesta (core, mantle and crust) is the key trait that makes Vesta more like planets such as Earth, Venus and Mars than the other asteroids, McCord said. Like the planets, Vesta had sufficient radioactive material inside when it coalesced, releasing heat that melted rock and enabled lighter layers to float to the outside. Scientists call this process differentiation.
This question immediately demonstrates once again the terrible mess the International Astronautical Union made when it decided several years ago to define what makes a planet, and came up with a definition that simply doesn’t work. For if Vesta should be considered a planet, why not Pluto?
New Horizons passes the orbit of Uranus on its way to Pluto
New Horizons has passed the orbit of Uranus on its way to Pluto.
Protest to reinstate Pluto as a planet
Right on! A protest to reinstate Pluto as a planet.
Ten Years On the way to Pluto
Alan Stern, project scientist of NASA’s mission to Pluto, New Horizons, gives his perspective ten years after the start of the project.
Pluto might be larger than Eris after all
The uncertainty of science! Eris, the distant planet in the Kuiper belt, had been thought to be larger than Pluto. Now astronomers have doubts.
Halfway to Pluto
The New Horizons space probe has now passed the halfway mark on its journey to Pluto.
Pluto’s ice: 97% nitrogen, 3% methane
More results from the press conference going on right now at the 42nd meeting of the AAS Division for Planetary Sciences:
Pluto’s surface ice is made up of 97% nitrogen, 3% methane, while the surface of the Kuiper Belt object Eris (which is larger than Pluto) is even more rich in methane, with a make up of 90% nitrogen and 10% methane. Both measurements go down to a depth of about 10 inches. To see the abstract for this result, go here.