Babe Among The Stars: A Close Shave and A Lucky Escape
Created | Updated Feb 27, 2013
Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth - Ptolemy
A Close Shave and a Lucky Escape
Friday 15 February was quite a red letter day for astronomers. We had been anticipating an asteroid fly-by, not only within the Moon's orbit, but also crossing the Clarke Belt (a loop of weather and communication satellites which orbit the Earth at a distance of 22,000 miles). This particular asteroid, 2012 DA14, missed our planet by 17,200 miles, or to put it another way, just half-an-hour in Earth's orbit. This was the closest near-miss since astronomers began recording such things, over 40 years ago.
Imagine the surprise then when on the morning of 15th, television screens were filled with images of a 50ft meteor which exploded over Russia, with debris making it to the ground near the town of Cherbakul. Nothing this big had impacted since the Tunguska event in 1908, also in Russia. The terrific speed of the meteor caused a sonic boom, and when it exploded, created a shockwave. Luckily no-one was killed although a reported 1,000 people were injured by flying glass. Witnesses reported that they thought it was the end of the world.
The odds against these unconnected events happening individually were quite high. The odds against both happening on the same day must be astronomical (pardon the pun). What's scary is, we were expecting the asteroid. The meteor took us by surprise. We live in a cosmic shooting-gallery and, as yet, have no defence against this supersonic extra-terrestrial ammunition. We were lucky this time...
2013 - the Year of the Comets
During March the first of this year's comets becomes more easily visible to the amateur astronomer. Comet PANSTARRS1 reaches perihelion on the 9th – it will attain its brightest peak then – zero magnitude is expected with −1 anticipated with relish2. This is one of the biggest thrills of astronomy, anticipation. We astronomers are disappointed so many times yet I have never known a lover of all things cosmic giving up their passion – most shrug (like I did, after last year's clouded-out transit of Venus), and start looking forward to the Next Big Thing. Comets, though, offer us a much better opportunity to get at least ONE satisfying viewing, because they're available to look at on more than one night, so we're not as dependent upon good weather. I can distinctly recall being driven to a dark-sky viewing area on a lovely clear night to gawp at the 'Great Comet of 1997' – Hale-Bopp. This despite the fact that I was able to see it quite clearly a number of times from the comfort of my own back garden. I just loved how it hung there in the sky, seemingly stationary, yet it was travelling at least 42km a second. How cool is that?
March 2013 Diary Dates
This month we will have many opportunities to see Comet PANSTARRS – try on the 12th and the 13th, the Moon will be a tiny crescent so won't drown the comet out. You'll need to be looking west after sunset, but do NOT use binoculars or a telescope in case you look at the Sun accidentally, until you are sure that the Sun has set. Comet PANSTARRS should be naked-eye as soon as it becomes dark, but it will soon set. Good luck and do let me know if you manage to spot this celestial visitor. If you miss out, don't worry, there's another comet on the way which promises to be much more spectacular.
- 01: The Moon passes 0.1° south of Spica (alpha Virginis)
- 02: The Moon passes 3° south of Saturn
- 03: Zubenelgenubi (alpha Librae), Saturn and the Moon line up
- 04: [approx 2.30am] Jabhat al Akrab (omega1 Scorpii) is occulted by the Moon
- 05: The Moon is at perigee (closest to Earth)
- 06: Polis (mu Sagittarii) is occulted by the Moon
- 06: Dwarf planet Ceres passes within 1° of El Nath (beta Tauri)
- 09: Comet PANSTARRS reaches perihelion (28m miles from the Sun)
- 10: The Moon passes 6° north of Neptune
- 11: New Moon
- 16: The Pleiades are grazed by the Moon
- 17: Conjunction of Aldebaran, Jupiter and the Moon
- 18: The Moon is at apogee (furthest from Earth) and occults Coronis (epsilon Tauri)
- 19: The Moon will be in the constellation Orion 'the hunter'
- 20: Vernal equinox
- 24: Jupiter passes 5° north of Aldebaran
- 24: The Moon will be in the constellation Sextans 'the sextant'
- 27: Full Moon
- 28: The Moon passes 0.005° north of Spica
- 29: The Moon passes 3° south of Saturn
- 30: The Moon is at perigee
- 31: [before sunrise] Mercury is 5° above the eastern horizon
- 31: Easter Sunday
- 31: British Summer Time begins
While researching this edition of BATS I learned something new, which is always a pleasure. I have mentioned it here. Can you guess what it was?
Chat about your celestial observances at the H2G2 Astronomy Society. Comment on anything in this edition of Babe Among the Stars by starting a new conversation below.