What is 5145 Pholus?
Q: What is 5145 Pholus?
A: 5145 Pholus is a Centaur (minor planetoid) of the solar system running in a stretched orbit, with a perihelion (closest approach to the Sun) less than Saturn's and aphelion (farthest approach from the Sun) farther than Neptune's.
Q: Who discovered 5145 Pholus?
A: 5145 Pholus was discovered by David L. Rabinowitz, then of the University of Arizona's Spacewatch Project.
Q: Why is it called "Big Red"?
A: It is called "Big Red" because it was quickly found to be very red in color. Astronomers think the color is because of organic compounds on its surface.
Q: When did 5145 Pholus last come within one astronomical unit (about 150 million km) of a planet?
A: The last time that 5145 Pholus came within one astronomical unit (about 150 million km) of a planet was 764 BC.
Q: When will it next come within one astronomical unit (about 150 million km) of a planet?
A: The next time that 5145 Pholus will come within one astronomical unit (about 150 million km) of a planet will be in 5290.
Q: Has there been any sign of cometary activity from this object?
A: No, there have been no signs of cometary activity from this object.
Q: What is estimated to be its diameter?
A: Astronomers think that Pholus' diameter is about 185±16 km.
