Dark Skies May Update

May Sky Map
6 years 3 months ago

Jupiter still continues to dominate our May evening skies, although the nights are becoming shorter and shorter as we draw into the Summer Solstice next month. Just after midnight, Mars and then Saturn will join Jupiter in becoming visible low in the SE skies.

Over the next few weeks, Mars will be brightening steadily, and will soon match Jupiter in brightness (or magnitude to use the correct astronomical terminology). This is due to the planet being closest to our Earth in Mid May as we both orbit our Sun. The reddy / orange hue of Mars will become very obvious, and through a telescope, a wealth of detail can be seen. Like our own planet, Mars has polar “ice caps” although not true water ice like ours. These grow and recede as the Martian seasons progress and darker areas are also noted against the orangey Martian deserts. The surface of Mars has slowly been relinquishing its secrets over the years due to the orbiting probes and surface rovers there. "Is there life on Mars?", as the late David Bowie famously asked in one of his many hits. The rovers have found no real evidence of such but can't really check in the best places on the planetary surface that may well give us some definitive answers. Until humankind steps foot on the surface of Mars, we’ll just have to wait and see what the rovers turn up.

Mercury is the other planet visible this month, although in a somewhat rare manner! Last month it was easily seen in the early evening skies, shortly after sunset as seen in the photo below. As it scoots around the Sun in its 88 day orbit, it passes between the Sun and our Earth, changing its visibility from evening time to morning times and so on. Roughly every 7-10 years, the Earth-Mercury-Sun alignment is such that Mercury appears to cross or transit the face of the solar disc. One such event occurs on the 9th May, with the transit starting at 12.12 BST and ending at 19.40 BST. The event is only visible with telescopes however as Mercury appears as a black dot only 1/150th of the solar disc. Please ensure that if you do wish to observe the Mercury transit with any optical instrument, you use correct solar filters on your telescope, or permanent blindness will be caused. Alternatively, join us at the Elan Valley visitor Centre for the transit event. Click here for full details. A composite photo of the last transit event is shown below.

And finally, for the early risers amongst us, there is one meteor shower active during the month. Visible low in the east-southeasterly early morning skies, the Eta Aquariid shower puts on a display until the end of the month with the maximum number of meteors around the 5th May. With a new moon around the same date, you may get lucky and see around 20-30 meteors per hour at most.

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Mercury on the horizon
Mercury in transit

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