Comet NEOWISE
What is Comet NEOWISE?
Comets· Nucleus ~5 km. The great comet of July 2020, seen with the naked eye across the northern hemisphere — the best naked-eye comet there since Hale–Bopp in 1997.
Past visits and the next return
Orbit and period
| Nucleus | ~5 km |
|---|---|
| Perihelion | 2020-07-03, 0.29 AU |
| Period | ~6,800 yr |
| Note | best northern naked-eye comet since 1997 |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
How NEOWISE's orbit was stretched on its way through
On its way into the inner solar system, NEOWISE took about 4,500 years to complete an orbit. After swinging around the Sun, its period grew to about 6,800 years. While the comet passed among the planets, their gravity, especially Jupiter's, gave it a little extra orbital energy, so it will now travel farther out than before.
A comet's orbit changes a little on every visit like this, so its next return has to be recalculated each time. NEOWISE's next visit is worked out to be around the year 8800, but that is only approximate. Near its farthest point, about 700 AU from the Sun, the gravity of passing stars can change its orbit again.
The comet in depth
Comet NEOWISE (C/2020 F3) was discovered on 27 March 2020 by NASA's infrared space telescope NEOWISE and was named after it. On 3 July it passed 0.29 AU from the Sun, even closer than the orbit of Mercury, the innermost planet. Some feared the Sun's heat would break it apart, but its nucleus, about 5 km across, survived intact.
In mid-July people across the northern hemisphere could see it with the naked eye, below the Big Dipper, in the north-east before dawn and in the north-west after dusk. Photographs showed a curved yellowish dust tail and a straight blue ion tail. Astronauts on the International Space Station photographed it rising beyond Earth's edge. It arrived during the COVID-19 lockdowns, and many people saw it from near their homes.
In the orbit view you can see its sharp curve dipping inside Mercury's orbit and quickly swinging back out. In the Sky view, go to the evening of 15 July 2020 (12:30 UTC) to see the comet low in the north-western sky. It is now heading away from the Sun and will not return for about 6,800 years.
Frequently asked
- How close does Comet NEOWISE get to the Sun?
- The perihelion of Comet NEOWISE is 2020-07-03, 0.29 AU.
- How long is the orbital period of Comet NEOWISE?
- The period of Comet NEOWISE is ~6,800 yr.
- What is notable about Comet NEOWISE?
- The note of Comet NEOWISE is best northern naked-eye comet since 1997.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.