What comets and asteroids are in the sky tonight?

Kieron Vernon, Coventry, UK, 11 July 2020. Equipment: Sony a7III camera, Sigma 24-70mm lens, ISO 800, 20x6”.

Comets, asteroids and other Near-Earth Objects (NEOs) are a fascinating sight to behold, if you can manage to spot one in the night sky.

Many will remember the appearance of Comet Hale-Bopp in the 1990s, or much more recently, the beautiful sight of Comet NEOWISE that made headlines around the world and enticed us all to take a look up at the evening sky.

Asteroid Vesta, for example, is one member of the Asteroid Belt that can also be seen, provided you know where and when to look.

But how do you spot comets and asteroids in the night sky? Find out in our guide below which comets and asteroids are visible tonight and over the coming weeks.

Kieron Vernon, Coventry, UK, 11 July 2020. Equipment: Sony a7III camera, Sigma 24-70mm lens, ISO 800, 20x6”.
Comet NEOWISE, photographed by Kieron Vernon, Coventry, UK, 11 July 2020. Equipment: Sony a7III camera, Sigma 24-70mm lens, ISO 800, 20×6”.

 

 

June 2021: See Asteroid 30 Urania

Asteroid 30 Urania was discovered by the English astronomer John Russell Hind on 22 July 1854. It reaches opposition on 14 June 2021, when it can be located against the stars of the constellation of Ophiuchus, the Serpent-bearer.

Urania is a main belt asteroid. Its shape and dimensions were measured using a technique known as speckle interferometry, which revealed the asteroid to be elliptical with a longest dimension of 111km and narrowest of 89km.

At its brightest it can be mag. +9.4, so this opposition doesn’t present it at optimal brightness. It takes 3.64 years to orbit the Sun, an orbit that takes it out as far as 2.67 AU and as close as 2.07 AU.

Urania is an S-type or siliceous asteroid, a class that has a stony or mineralogical composition. S-type asteroids account for about 17% of asteroids.

Diagram showing the path of Asteroid 30 Urania in the sky throughout June 2021
Use a small telescope to track 30 Urania’s progress over June. Credit: Pete Lawrence

Strictly speaking Urania starts the month in Sagittarius, the Archer, 2˚ north of mag. +4.2, 3 Sagittarii. This positions it very close Sagittarius’s western border and tracking west.

It’s not long before Urania crosses this invisible demarcation line, slipping into Ophiuchus in the early hours of 3 June.

Urania remains above or equal to mag. +11.0 all month, a viable target for a small telescope, but beyond average binocular range.

Its track this month takes it 2˚ south of the mag. +7.4 globular cluster NGC 6401 on the nights of 6/7, 7/8 and 8/9 June.

It passes 0.5º south of mag. +3.3 Theta (θ) Ophiuchi on 22/23 June.

By the month’s end, it’s located 4˚ east-northeast of the mag. +6.8 globular cluster M19. The bright skies found near the June solstice will make locating even a mag. +11.0 object trickier than normal.

July 2021: minor planet 12 Victoria 

Track 12 Victoria’s progress over July 2021 with a small telescope. Credit: Pete Lawrence
Track 12 Victoria’s progress over July 2021 with a small telescope. Credit: Pete Lawrence

Minor planet 12 Victoria reaches opposition in July 2021. On 1 July it shines at mag. +9.3, slowly brightening over the rest of the month to a peak of mag. +8.8 at opposition on 30 July.

This makes it an ideal object to find and track with a small telescope.

On 1 July 12 Victoria is located in northwest Aquarius, close to the border with Aquila. This region lacks any really bright stars: the best guides are the mag. +4.4 star 3 Aquarii and 70 Aquilae at mag. +4.9.

On 1 July 12 Victoria sits two-thirds of the way along a line from 3 Aquarii towards 70 Aquliae. Its path arcs as it tracks northwest.

At its brightest, near the month’s close, it lies about 2.5˚ east and a fraction south of mag. +3.2 Theta (θ) Aquilae.

The best way to identify 12 Victoria is to sketch or image the field you suspect the asteroid to be located within over the course of several nights.

If 12 Victoria is in this field, its movement will reveal it. In order to achieve this, the field must be recorded with field stars below the threshold of the asteroid, say at least mag. +9.5.

Models of asteroid 12 Victoria. Credit: Astronomical Institute of the Charles University: Josef Ďurech, Vojtěch Sidorin
Models of asteroid 12 Victoria. Credit: Astronomical Institute of the Charles University: Josef Ďurech, Vojtěch Sidorin

12 Victoria was discovered on 13 September 1850 by John Russell Hind. Although officially named after the Roman goddess of victory, it was also named in honour of Queen Victoria.

It’s a siliceous or stony (S-type) asteroid, around 120km-across, orbiting within the main belt between Mars and Jupiter.

Its apparent magnitude varies between +8.7 and +12.8, making this opposition quite favourable.

12 Victoria’s orbit takes it out as far as 2.85 AU and in as close as 1.82 AU from the Sun.

Studies of its elongated shape suggest that it might be a binary object, the primary chunk having an irregular shaped moon in mutual orbit around it.

Pete Lawrence is an experienced comet and asteroid observer and a co-host of The Sky at Night.