Key Facts About Comets in Our Solar System to Know for Intro to Astronomy

Comets are fascinating celestial objects that offer insights into our solar system's history. From Halley's Comet to the bright Hale-Bopp, these icy bodies reveal the dynamic processes at play in space, making them essential for understanding astronomy.

1. Halley's Comet

   • One of the most famous comets, visible from Earth approximately every 76 years.
   • Last appeared in 1986 and will return in 2061.
   • Named after astronomer Edmond Halley, who calculated its orbit and predicted its return.

2. Comet Hale-Bopp

   • Discovered in 1995, it became one of the brightest comets of the 20th century.
   • It had a long visibility period, remaining visible to the naked eye for nearly 18 months.
   • Its nucleus is estimated to be about 40 kilometers wide, making it one of the largest known comets.

3. Comet Shoemaker-Levy 9

   • Famous for its collision with Jupiter in 1994, providing a unique opportunity to observe impacts.
   • Discovered in 1993, it was the first comet observed to be in orbit around a planet.
   • The event highlighted the potential hazards of comets and asteroids to planetary bodies.

4. Comet Hyakutake

   • Discovered in 1996, it made a close approach to Earth, coming within 15 million kilometers.
   • Known for its long tail, which extended over 100 million kilometers.
   • It was one of the brightest comets of the 1990s, visible to the naked eye.

5. Comet ISON

   • Discovered in 2012, it was anticipated to be a "comet of the century" due to its close approach to the Sun.
   • It disintegrated during its perihelion passage in 2013, disappointing many observers.
   • Its study provided insights into the behavior of comets as they approach the Sun.

6. Comet 67P/Churyumov-Gerasimenko

   • The target of the European Space Agency's Rosetta mission, which studied the comet up close.
   • It has a unique duck-shaped appearance and is composed of two lobes.
   • The mission provided valuable data on the composition and behavior of comets.

7. Comet Tempel 1

   • Known for being the target of NASA's Deep Impact mission in 2005, which impacted the comet to study its interior.
   • The impact created a crater and allowed scientists to analyze the material ejected.
   • It orbits the Sun every 5.5 years, making it a relatively short-period comet.

8. Comet Wild 2

   • Studied by NASA's Stardust mission, which collected samples from its coma in 2004.
   • The samples returned to Earth provided insights into the early solar system's conditions.
   • It has a highly elliptical orbit, taking about 6.4 years to complete one revolution around the Sun.

9. Comet Encke

   • Notable for having the shortest orbital period of any known comet, approximately 3.3 years.
   • Its frequent returns make it a valuable subject for studying cometary behavior.
   • The comet is associated with the annual Perseid meteor shower.

10. Comet Lovejoy

    • Discovered in 2011, it became notable for its bright appearance and long tail.
    • It survived a close encounter with the Sun, demonstrating the resilience of some comets.
    • Its visibility to the naked eye made it a popular target for amateur astronomers.