161P/Hartley-IRAS (2026)

Capture

Seestar s50 Pro 105 stacks

Date

6 October 2026

Location

Camden, NSW

Original

1586 × 2668 px

161P/Hartley-IRAS (2026) is a periodic Halley-type comet with an orbital period of about 21.5 years. It has a strong connection to New South Wales: Malcolm Hartley first caught its trail on a photographic plate at Siding Spring Observatory on 4 November 1983. Six days later the infrared space telescope IRAS also detected it. Its orbit is tilted about 95.8°, almost at right angles to the paths of the planets and just far enough over to count as retrograde, meaning it travels in the opposite direction to them. The orbit is also highly eccentric (0.836), carrying the comet from 1.265 AU from the Sun out to about 14.2 AU, between Saturn and Uranus. It made its closest approach to Earth on 2 October 2026, at about 0.503 AU (75.3 million km), and reaches perihelion (its closest point to the Sun) on 27 November 2026. The comet was moving so fast against the stars that it appears as a streak in this image. Its magnitude at the time of observation was around 11 to 12.

See it in the comets gallery