perihelion
New Evidence for Our Solar System’s Ghost: Planet Nine
Does another undetected planet languish in our Solar System's distant reaches? Does it follow a distant orbit around the Sun…
ESA’s Solar Orbiter Takes a Ludicrously High Resolution Image of the Sun
The European Space Agency’s Solar Orbiter snaps an amazing image, en route to its first close pass near the Sun.
Spectacular Celestial Fireworks Commemorate Perihelion Passage of Rosetta’s Comet
Sequence of OSIRIS narrow-angle camera images from 12 August 2015, just a few hours before the comet reached perihelion. Credits:…
How Long Does It Take to Get to Pluto?
It's a long way out to the dwarf planet Pluto. So, just how fast could we get there? Pluto, the…
How Did We Find the Distance to the Sun?
How far is the Sun? It seems as if one could hardly ask a more straightforward question. Yet this very…
The Orbit of Earth. How Long is a Year on Earth?
Ever since the 16th century when Nicolaus Copernicus demonstrated that the Earth revolved around in the Sun, scientists have worked…
NASA’s STEREO Spacecraft Spots Comets ISON and Encke
As comets ISON and Encke continue toward their respective rendezvous with the Sun, they have now both been captured on…
This is Comet ISON Seen From Mars
It's not much to look at, but there it is: the incoming comet ISON (aka C/2012 S1) as seen by the…
New Comet Discovered: Lovejoy Will Add to “Comet Lineup” in Winter Skies
Move over Comet ISON. You've got company. Australian amateur astronomer Terry Lovejoy, discoverer of three previous comets, including the famous,…