page_title: 90377 Sedna
hierarchical_section_title: 90377 Sedna
caption_attribution_description: In this artist's visualization, the newly discovered planet-like object, dubbed "Sedna," is shown where it resides at the outer edges of the known solar system. The object is so far away that the Sun appears as an extremely bright star instead of the large, warm disc observed from Earth. All that is known about Sedna's appearance is that it has a reddish hue, almost as red and reflective as the planet Mars. (Digitally REMOVED: In the distance is a hypothetical small moon, which scientists believe may be orbiting this distant body.)
context_page_description: 90377 Sedna is a large trans-Neptunian object. It was discovered on November 14, 2003 by Mike Brown, Chad Trujillo and David Rabinowitz. Around 1250-1800 km in diameter, Sedna takes roughly 10,500 years to orbit the Sun, much higher than most known trans-Neptunian objects. It is one of the most distant known objects in the Solar System. Therefore, Sedna's surface temperature never rises above -240°C.
  The name "Sedna" comes from the Inuit goddess of the sea, thought to live at the bottom of the Arctic Ocean.
  NASA is not currently planning any space missions to explore Sedna, but there is some talk of missions to happen when Sedna reaches perihelion again. It is considered to be a likely candidate as a dwarf planet.
  No pictures can be taken of Sedna because very little light from the Sun reaches it. For this reason, Sedna is known as "Cobian", meaning shadows in Ancient Greek. Due to its orbit, the chances of Sedna being found were 0.017%. 40-120 more objects this size should exist without us knowing, but, as they are so small and far away, they may not be discovered for a while.
context_section_description: 90377 Sedna (or simply just Sedna) is a large trans-Neptunian object. It was discovered on November 14, 2003 by Mike Brown, Chad Trujillo and David Rabinowitz. Around 1250-1800 km in diameter, Sedna takes roughly 10,500 years to orbit the Sun, much higher than most known trans-Neptunian objects. It is one of the most distant known objects in the Solar System. Therefore, Sedna's surface temperature never rises above -240°C.
  The name "Sedna" comes from the Inuit goddess of the sea, thought to live at the bottom of the Arctic Ocean.
  NASA is not currently planning any space missions to explore Sedna, but there is some talk of missions to happen when Sedna reaches perihelion again. It is considered to be a likely candidate as a dwarf planet.
  No pictures can be taken of Sedna because very little light from the Sun reaches it. For this reason, Sedna is known as "Cobian", meaning shadows in Ancient Greek. Due to its orbit, the chances of Sedna being found were 0.017%. 40-120 more objects this size should exist without us knowing, but, as they are so small and far away, they may not be discovered for a while.
caption: What 90377 Sedna may look like.
exif: {"Image Copyright": "2004 Getty Images"}