Star Spy: Bunny on the Moon

17:00, Jun 25 2012
Messier 4 (M4)
Messier 4, or M4 for short, is a ball of stars with some of them almost as old as our galaxy.
First quarter moon
The rabbit shape on the surface of the moon is of a region known as the Sea of Tranquility.
Reflected Nebula
To capture the colours of the reflected nebula you need a timelapse photograph.
Rho Ophiuchi
Rho Ophiuchi is one of the closest stellar nurseries to Earth - it is a place where stars are born.

The Rabbit in the Moon

If you look closely at the first quarter moon this week you will notice two long gray rabbit ears sticking up on the left side, with a gray head just below them, and the body sort of curled around to the right below the head.

The head of the rabbit is a region known as the Sea of Tranquility.

Mare Tranquillitatis is the Latin name given to it by early astronomers who thought the dark areas on the Moon were large bodies of water.

The children's version of the rabbit (see picture above) is winking so that you can see the area, in the open eye, where the "giant leap for mankind" was made by the Apollo 11 astronauts.

We now know that these large dark areas on the moon are not bodies of water (maria), rather they are plains of solidified basaltic magma formed by volcanoes in the Moon's ancient past.

Surprises in Scorpius

Hidden within and around Scorpius in our sky are many fascinating celestial objects, with Antares in particular surrounded by the colourful clouds of dust and gas in Fraser's image from last week.

Looking deeper into that view this week we find a globular cluster (roughly speaking - a ball of stars) called simply Messier 4 or M4, as it was the fourth fuzzily-glowing object catalogued by 18th Century French astronomer Charles Messier.

He was searching for comets, also fuzzily-glowing objects, but ones which are moving quickly through the solar system, so he catalogued the more permanent objects that were similar in appearance, mainly to eliminate them from his search.

His catalogue of deep sky objects, some of which are part of our galaxy, others being distant separate galaxies, is still in use today.

M4 is too dim to see with just our eyes, but it actually covers an area about the size of the full moon in the sky, just above and well beyond Antares. Its stars are almost as old as our galaxy.

You may also recognise from the wider view of the Antares region the blue cloud expanded from the bottom left. This is the Rho Ophiuchi cloud complex in its natural colour.

It contains baby stars that are still in the process of being born and is one of the closest stellar nurseries to us.

You need a small telescope to see these distant and beautiful objects, and a time-lapse photograph to capture the colours as Fraser has done (see picture above).