Three reasons to look to the stars
By Will Goodbody, Science & Technology Correspondent
It’s been an exciting week for star-gazers, with the remarkable rendez-vous between the European Space Agency’s Rosetta probe and comet 67P/Churyumov–Gerasimenko. For a man-made object to travel 6 billion kilometres unscathed around the solar system over a decade and still manage to catch and begin orbiting a 4 kilometre target moving at 55,000 kmp/h is extraordinary. And happily, the best is yet to come, as Rosetta prepares to monitor and send a lander down onto the comet’s surface – unlocking, it’s hoped, wonderful secrets about life.
But back on Earth, the space fest is set to continue this weekend. Because Sunday and the early days of next week could end up being a super celestial showcase. According to the Irish Astronomical Association (IAA), on August 10th Ireland will enjoy its best SuperMoon until 2018, followed two days later by the peak of the Perseid Meteor Shower and a great series of passes by the International Space Station.
Supermoons occur when a full Moon coincides with the time the Moon is closest to Earth in its elliptical orbit – otherwise known by astronomers as perigee. At this closest point the Moon will be a mere 356,410 km from Earth – a short hop in space terms, and a whole 50,000km nearer than it is when it is at its maximum distance away. The effect is to make the full Moon appear even larger, brighter and closer than it otherwise would. The timing for Ireland is very good, according to the IAA, with perigee happening just before the full Moon takes place and rises here. Look to the rising Moon in the south eastern sky, around the time the sun sets at 9pm, to witness a lunar spectacle unlikely to be bettered before the 1st January 2018.
Ironically, the bright Moon could compromise a spectacular celestial fireworks display due to take place over the following nights. Once a year, the Perseid meteor shower takes place, when tiny bits from comet Swift-Tuttle smash into Earth’s upper atmosphere at huge speed, creating “shooting stars” as they burn up. The Perseid peak, with up to 100 an hour visible, takes place on August 12th and 13th, and in theory they can be seen in all parts of the sky, though closer to dawn may prove better given the brightness of the moon.
But one spectacle which it will be harder to miss over the coming weeks will be the International Space Station. The largest man-made object ever put into space, the Croke Park sized object should be visible before and after midnight until August 21st, and then after that in the evening skies. It appears like a bright star travelling west to east, speeding up as it goes. Check out websites like astronomy.ie/iss and http://spotthestation.nasa.gov/sightings/ to find out where and when to look.
According to IAA, if you get very lucky, from around 2220 on Sunday night you might be lucky enough to see all three spectacles. Of course viewing all these celestial wonders is heavily dependent on the weather. Which unlike the movement of the Sun, Moon, stars and ISS, is unfortunately highly unpredictable!