The year 2012 has been a busy one. Both predicted and surprise sky events and milestones in solar system exploration gave astronomy lovers plenty to be happy about. After a long hiatus during the extended solar minimum, the aurora borealis finally burst back into the limelight for observers living in mid-northern latitudes. Here in Duluth, Minn. we saw northern lights on at least two dozen occasions this past year.
Wanna talk planetary alignments? There were plenty, plus asteroid flybys, eclipses, a rare transit of Venus, great meteor showers and it was all topped off by the end of the world on December 21. I’ve prepared a list of what I think were 2012’s highlights below. Enjoy the read, and if you think I missed one of your favorites, by all means, let us know!
* March 3 – Opposition of Mars: Mars pulled up alongside Earth for one of its every-two-year close approaches to our planet. At the time the Red Planet lodged in Leo and shone at magnitude -1.2, nearly as bright as the brightest star Sirius. On several occasions, amateur astronomers, armed with sophisticated cameras, recorded high clouds hovering above the edge of Mars.
* March 8-9 – Big auroral display: One of the first large northern lights shows of the year and a good omen for what was to come. Solar activity ticked up all year long as the sun approached the expected maximum of its current cycle next spring.
* March 27 – Greatest elongation of Venus in the evening sky. Venus caught our eye all winter and spring in the western sky at dusk, often meeting up with the moon for beautiful conjunctions. The planet also had one of its infrequent conjunctions with the Pleiades star cluster on April 3.
* April 22 – Sutter’s Mill meteorite fall. 1st fragments recovered April 24 near Sutter’s Mill, California. More meteorite falls followed including Battle Mountain, Nevada (Aug. 22), Novato, California (Oct. 17) and northern Alabama (Oct 30). In all cases, the relatively new technique of reading Doppler weather radar data was used to see the tracks of the falling fragments and plot likely locations of fallen meteorites. Sutter’s Mill turned out to be a rare carbon-rich meteorite called a carbonaceous chondrite.
* May 15 – Bright supernova discovered: SN 2012 cg in the galaxy NGC 4244 in Virgo reached magnitude 11.9 and could be seen even in small scopes. This Type Ia supernova involved the complete annihilation of a white dwarf star. A second bright supernova, SN 2012fr, also a Type Ia, popped off in the bright southern galaxy NGC 1365 in Fornax on Oct. 27. It also reached magnitude 11.9.
* May 20 – Annular eclipse of the sun: Seen by many, the eclipse path reached from China as far as the western U.S. Annular or ring eclipses happen when the moon is farther from Earth than usual. When it crosses directly in front of the sun, it doesn’t cover it completely, leaving a ring of sunlight. A partial eclipse was seen across much of the U.S. and enjoyed by yours truly in Duluth near sundown.
* May 26 – SpaceX launches the Dragon ship to the International Space Station: 1st private, non-governmental expedition to the station and the start of what’s likely to become a new paradigm – the private enterprise exploration of space.
* May 29 – Asteroid 2012 KT42 sails 8,700 miles past Earth: A tiny orb only 10-30 feet wide misses Earth. It was one of many near-Earth asteroid flybys. Other close shaves this year included 2012 TC4 (59,650 miles on Oct. 11) and 2012 XE54 (139,500 miles on Dec. 10).
* June 5 – Transit of Venus: Transits happen when Venus passes directly in front of the sun, appearing an inky black dot against the brilliance solar surface. Venus transits happen in pairs 8 years apart separated by intervals of 121.5 and 105.5 years. The last occurred in 2004 and the next will happen on December 10, 2117. That means this was the last transit just about everyone currently alive on Earth will see.
* June 16 – China successfully launches three astronauts including that country’s first woman, Liu Yang, into space. Their crew docked with the Tiangong 1 laboratory module and spent about three weeks in Earth orbit.
* June – Voyager I reached the heliosheath: At 11.1 billion miles from Earth, NASA’s 35-year-old planetary probe entered the heliosheath, a buffer zone where the sun’s influence wanes and the frontier of interstellar space begins. The craft is expected to pass beyond the heliosheath and leave the solar system behind sometime between the next few months and two years.
* Late June – Jupiter’s northern equatorial belt (NEB) discovered in meteorological upheaval when the planet emerges again in the dawn sky after conjunction with the sun. The belt erupted in dark spots and patches and now appears distinctly wider than it did a year ago.
* July 14 – Spectacular all-night display of the aurora borealis: This one glowed with beautiful greens and purple-reds and continued until dawn, when the crescent moon, Jupiter and Venus joined the show. Another sleep-depriving aurora hit overnight on November 13-14.
* July 13 – Announcement of a fifth moon found orbiting the dwarf planet Pluto. Discovered with the Hubble Space Telescope, S/2012 (134340) is only 6-15 miles across.
* Late July and early August – Multiple triangle-shaped gatherings and conjunctions of Saturn, Mars and the star Spica in the evening sky.
* August 6 – Curiosity rover makes a flawless touchdown on Mars:The 1-ton robotic laboratory survives its 7-minutes-of-terror landing sequence and successfully lands on the Red Planet. We’re all jubilant. The rover will study Mars’ climate, geology and whether the planet once offered an environment suitable for life.
* August 11-12 – The annual Perseid meteor shower: A maximum of about 100 per hour were recorded during the peak. With little interference from the moon, skywatchers enjoyed a great show.
* September 5 – Dawn spacecraft departs the asteroid Vesta: After more than a year of study and more than 31,000 photos, NASA’s Dawn probe departed Vesta and sped off toward its next target, the asteroid Ceres. It arrives there in early 2015.
* September 10 – Impact on Jupiter: Amateur astronomer Dan Peterson of Racine, Wis. spotted a white flash on Jupiter through his 12-inch telescope. At the same time, another amateur astronomer, George Hall of Dallas, Tex. recorded the impact with a webcam on his scope. The object was likely a small asteroid or comet.
* September 25 – Hubble takes deepest image of universe ever: Combining 2,000 separate images made with a total exposure time of 23 days, the photo shows over 5,500 galaxies in an area of sky 1/10 the size of the full moon. The most distant galaxies in the image are over 13 billion light years away.
* September 27 – Curiosity finds ancient streambed gravels: The rover mission discovered evidence of a stream that once ran vigorously across Gale Crater. Pictures show ancient streambed gravels rounded by the action of flowing water — a first of its kind.
* Early October – Comet Hergenrother shines: Along with the more recent C/2012 K5 (LINEAR), 168P/Hergenrother became one of the two brightest comets of the year with a lovely tail to boot. While not visible with the naked eye, it was a beautiful sight in the Great Square of Pegasus shining around 9th magnitude.
* October 16 – Earth-sized planet discovered orbiting Alpha Centauri, the nearest star beyond the sun: Astronomers using a spectrograph on the European Southern Observatory’s 142-inch telescope in La Silla, Chile found the planet orbiting 3.7 million miles from Alpha Centauri B (one of the three stars in the Alpha Centauri system). Sadly, that’s too close for comfort. The extreme heat makes it an unlikely place for life.
* October 29 – Full moon magnifies Hurricane Sandy’s storm surge: The hurricane got an unwanted boost from the combined effects of the sun and an especially close full moon
* November 14 – Total solar eclipse across Australia and the South Pacific.
* November 29 – Compelling evidence for ice at Mercury’s poles: NASA’s MESSENGER spacecraft detects ice in the shady regions near the planet’s poles. The material is likely material from long-ago impacting comets that’s been in deep freeze ever since.
* December 3 – Mercury-Venus-Saturn planetary alignment: Widely misrepresented on the Web as appearing equally spaced over the tops of the three pyramids of Giza, the grouping was pretty to see just the same.
* December 13 – Maximum of the Geminid meteor shower: Wonderful and consistent shower threw over 100 meteors an hour our way at peak. No moon interfered.
* December 13 – Chinese flyby of asteroid Toutatis: The Chinese space probe Chang’e 2, originally intended to orbit and study the moon, was re-directed to make a close flyby of the Earth-approaching asteroid 4179 Toutatis. The mission proved a spectacular success.
* December 21 – Day the world was supposed to end: Misinterpretation and hype surrounding the Mayan calendar had some people very concerned. Others saw it as good entertainment. We all know now how it played out in the end.
* December 25 – Jupiter-moon conjunction: One of the best and brightest pairings of the year.
Tomorrow we’ll take a look at what lies ahead in 2013!