Adrian Dening's Stars Over Somerset

Wednesday, 21 February 2024 17:00

Monday 26th February to Sunday 3rd March 2024

How about a bit of asteroid hunting? On the evening of Saturday 2nd March at around 8pm, the constellation of Leo will be located towards the east. Just below Leo will be the minor planet or asteroid known as Juno. You will need a telescope to find it as the magnitude is currently around +8.6 making it invisible to the naked eye.

Juno was first discovered in 1804 and was actually only the third asteroid ever identified. Officially, its correct full name is "3 Juno" as a result. Initially it was classed as another regular planet, but in the 1850s Juno was downgraded to the status of being a minor planet or big asteroid!

Juno is actually the tenth largest asteroid, with a diameter of approximately 250Km. Being part of the asteroid belt between Mars and Jupiter, its orbital period (or the length of time it takes to go around the Sun) is 4.3 times longer than ours. The Earth's orbital period is 365 1/4 days, but a year is rounded down to 365 days to keep it simple. What do we do with the missing quarter days.....every four years we add one extra day, 29th February and call it a leap year.

I have provided a star chart to help you try and locate Juno together with an image of it captured by the Very Large Telescope / Sphere Team at the European Southern Observatory in Chile.

Alternatively, a much easier target will be a Last Quarter Moon which at 5am on Sunday 3rd March will be located towards the south, with the red giant star Antares to the left of it.