May is a great month for viewing planets!

The five major planets in our solar system are all easily visible to the unaided eye, which is why they have been known about since antiquity. If you have never seen a planet before, this is a good month to start looking for them. The only planet that cannot be seen this month is Venus, which is too close to the blindingly bright Sun to spot.

The sun sets at 20:45 BST mid-month, with nautical twilight (when the Sun falls to 12 degrees below the horizon) ending at 22:24 BST - although it does not get astronomically dark until 23:52 BST.

Even though it is still twilight at 21:45 BST, this is the best time to look for the planet Mercury.

Because Mercury is the closest planet to the Sun, orbiting the Sun in just 88 days, it is always pretty close to the Sun in the night sky. But, every 3 months there are a brief few days when Mercury gets to the extreme of its orbit - this is the time to spot it in the evening sky after sunset.

Look low in the bright north-western sky to find Mercury, the best times being between the 5th and 10th of May, about 45 minutes after sunset - that is the time when the sky is dark enough to see Mercury, and Mercury has another hour yet before it follows the Sun below our horizon.

The ideal date to look is on the 6th of May, when Mercury is just to the left of the beautifully young crescent Moon. Having a flat clear horizon also helps, so gazing out to sea looking west is the best way to spot the planet.

Mars is visible towards the west throughout the evening, easily recognisable thanks to its red colour. The Moon acts as a useful guide on the 10th of May, when it is just to the left of Mars.

Saturn is visible until the early morning, always in the western sky. Through even the smallest telescope, you can see the rings that surround this majestic planet. On the 12th, the Moon moves into position just below the planet.

And finally, at around midnight, the planet Jupiter is rising in the east, with the Moon beside it on the 24th and 25th.

I bought a new digital camera a few weeks ago, and I was very impressed by its resolution - a whopping10 Mpx! (10 million pixels). But that is tiny compared to the digital camera involved in the University of Hawaii's Pan-STARRS project...

Their digital camera is a staggering 1,400 Mpx!

I would have to buy another 139 cameras to compete with that!

Pan-STARRS main aim is to repeatedly photograph the sky looking for potentially hazardous asteroids - we only know of 953 PHA's at the moment (according to SpaceWeather.com). Having said that, they will also be able to do lots of other interesting science as well, such as looking for variables stars (e.g. supernovae).

This project continues in the great tradition of astronomers leading the way in digital camera technology. The first CCD (a type of digital camera sensor) was used on the Kitt Peak National Observatory's 1m telescope all the way back in 1979. This CCD was 50x more sensitive than film. It took until 1990 for the first commercial digital camera became available, and now, almost everybody has one!

• NMM job opportunities: Director, Royal Observatory Greenwich
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To see a satellite from the ground, you need them to fly over at just the right time - either dawn or dusk. In daytime, the sky is too bright to see them. At night, the satellites are in the shadow of the Earth an so cannot be seen.

The next six weeks are the perfect time to see the space station flying over head.

The amazing image to the left were taken by Dirk Ewers of Hofgeismar, Germany, using just a 5 inch refracting telescope!

If you want to see the space station fly overhead, all you need to know is when and where to look - which the very easy-to-use SpaceWeather.com satellite tracker will tell you.

The International Space Station can get extremely bright. Don't forget - If you see something passing over head with a flashing light, then it is a aircraft! If it has a constant brightness, it is a satellite. Also, satellites disappear suddenly as they enter the shadow of the Earth.

The NASA Phoenix mission to Mars has landed on the surface of Mars intact!

Previous missions have shown large amounts of subsurface water ice in the northern arctic plain. The Phoenix lander targets this region and will use a robotic arm to dig through the protective top soil layer to the water ice below and ultimately, to bring both soil and water ice to the lander platform for sophisticated scientific analysis.

Controllers were able to receive data for a minute after the landing, enough data to confirm that the lander was tilted by just one quarter of a degree!

"In my dreams, it couldn't have gone as perfectly as it went tonight," says Barry Goldstein, the Phoenix project manager. "I'm in shock. We had all the signals. Everything."

"It's in a nice flat place, very safe and happy," says Peter Smith, the Phoenix principal investigator.

An animation showing the landing is available here, and the first image back will be available on APOD.

The main activity of the mission controllers immediately after launch was phoning and texting friends and family, updating them on their success!

The lander meanwhile will wait for 20 minutes for the dust to settle, before opening its solar panels. The Mars Odyssey spacecraft will next fly over the landing site in about 2 hours time, and it will be then (around 02:00 GMT) that the first pictures from the surface of Mars may be sent back to Earth.

The first photographs from Mars Phoenix are now available at:

• BBC News
• NASA Phoenix
• University of Arizona

The decent of the Mars Phoenix lander (and its parachute) was captured by the Mars Reconnaissance Orbiter HiRISE camera... And what an amazing photograph.

Note that, although it looks like the Phoenix is landing inside the crater, it is actually about 20km in front of the crater.