Each year of this decade brought at least one memorable astronomical event. Everyone remembers something that stands out, such as the transits of Venus and Mercury, the partial solar eclipse, the close approach of a dusty Mars, or one of the total lunar eclipses. The official decade runs from January 1, 2011 through December 31, 2020, but somehow it seems more appropriate to look at the years from 2010 to 2019. The following are considered the most significant and memorable celestial events of the past ten years.
2010: The one event that stands out came during mid-October with Comet Hartley 2 appearing as a ghostly puffball below the Double Cluster. The Deep Impact spacecraft flew within 435 miles of it on November 4 revealing it to be bi-lobed, shaped like a steaming chicken drumstick. A total lunar eclipse occurred during the wee morning hours well before sunrise on December 21, but was clouded out.
2011: The year began with Uranus and Jupiter very close together in the evening sky offering an excellent opportunity to easily find Uranus and compare it in color and size to Jupiter. Comet Garradd made a beautiful showing during late July with a compact coma and a bright core that developed a stubby tail later in August. The tail nearly swept over M71, a globular cluster in Sagitta for a beautiful pairing during late August.
2012: The best astronomical event of this decade occurred on June 5 when Venus transited the Sun during the evening. The Sun set before Venus could transit completely across, but the threatening weather cooperated as this was the last Venus transit visible in this area until December 8, 2125.
2013: Comet PANSTARRS appeared very low in the west in the evening during March but never grew very bright; it was mainly forgotten due to poor weather. A penumbral lunar eclipse was visible during the evening of October 18; it was deep enough and the skies perfectly clear to easily see the subtle shadow. This allowed for good photos of a dusky shadow at its maximum. This year was also known for the comet of a lifetime that never was when Comet ISON broke apart after passing within 600,000 miles from the Sun on November 28, and disintegrated.
2014: A busy year of observing began with a stumble as a total lunar eclipse during the morning of April 15 was mainly clouded out, but a few precious breaks occurred during totality, which allowed brief glimpses of the rusty Moon. Comet Jacques was a nice comet and a beautiful sight as it appeared as a puffball near Alberio on September 14. Another total lunar eclipse occurred just before sunrise on October 8 and was successfully seen locally, although this author increased the odds of good weather by successfully viewing it from Disney World! A partial eclipse of the Sun on October 23 was 25% eclipsed as it set, but it was rained out.
2015: This was another great year and started off right away with a spectacular view of Comet Lovejoy passing near the Pleiades during mid-January, and even though it was only a typical fuzzy ball, it could be seen with the unaided eye using averted vision. Seeing a comet paired with the Pleiades with only unaided eyes, even if it is averted vision, is something never to be missed, and this comet delivered for a delightful, if chilly memory. A slight partial lunar eclipse on April 4 shortly before sunrise was clouded out. This year delivered the best total lunar eclipse of this decade during the evening of September 27. The weather cooperated enough with only a few clouds, and was reasonably mild to add to the enjoyment. This lunar eclipse was a rich red to bloody colored one and highly photographed.
2016: Another rare astronomical event occurred this decade and miraculously the weather cooperated again! Mercury transited the Sun beginning shortly after sunrise and ending during the early afternoon on May 9. The entire transit was seen with no problem allowing for many photographs. Mars had a reasonably close approach to Earth from April into early summer allowing for the best views of its surface details since 2005.
2017: A partial solar eclipse was successfully observed locally with 67% of the Sun eclipsed at 2:39 P.M. and appeared as an upside-down crescent. This was the Great American Eclipse that was successfully seen totally eclipsed in Santee, South Carolina by this author. The last partial solar eclipse that was successfully seen locally was on Christmas Day 2000, so these are rare events. The next partial eclipse comes on June 10, 2021 with the added challenge that it occurs at sunrise, but April 8, 2024 brings totality nearby! Fingers crossed!
2018: A slight partial lunar eclipse on January 31 shortly before sunrise was barely visible on the horizon with high clouds filtering it in the brightening sky. Mercury and Venus made a beautiful close pairing in the evening during mid-March that was successfully seen over several evenings in spite of a cold and very stormy month. Mars was at its best, largest and brightest since 2003, during July and August, but was bothered by a global dust storm that hindered viewing surface details until it finally settled in August. Comet Wirtanen was the Christmas Comet that was observed by many during mid-December as it passed between the Pleiades and Hyades. It was a bright, compact, fuzzy ball and a beautiful shade of emerald green in photographs.
2019: A very high midnight total lunar eclipse was successfully observed on January 20-21 in spite of the subzero cold. It was a bright one displaying rich colors, ranging from a bloody red chin to a bluish-gray forehead and shades of rust, orange, and gold in between. The last transit of Mercury across the Sun until May 7, 2049 occurred on November 11, but was clouded due to the approach of an early winter storm.
It was an exciting decade of astronomical events, but at times frustrating when the weather often challenged observing and won out, but there were big successes when needed most. The biggest victory was the 2012 Venus transit, which will never be seen again during our lifetimes. This event is truly remembered and cherished by all who saw it. The new decade ahead will have a good mix of partial and total lunar eclipses and partial solar eclipses, and surprises, such as a possible bright comet or aurora. However, there is one rare event that will demand nice weather. A total eclipse of the Sun passes nearby on April 8, 2024! If the weather cooperates it will be not only the memory of the decade, but truly THE memory of a lifetime!