On April 19th a considerable sized asteroid will pass about 4.6 lunar distances (1.8 million km) from Earth. While there is no chance of it impacting our planet, this 650m asteroid was only discovered three years ago, and it will be the closest encounter of a large asteroid since asteroid Toutatis in September 2004. The next predicted fly-by of a large asteroid is 2027 with 800m wide 1990 AN10.
The expected magnitude could reach up to 11 during the close approach, hence a decent sized scope will be required, and due to the rapid movement may be hard to locate and track.
Sky chart for asteroid 2014 JO25 covering April 18th to 20th 2017
And as a bonus, comet PanSTARRS (C/2015 ER61) will also make its closest approach to Earth on the 19th, but 10 times farther away as the asteroid. I should be visible with small telescopes or binoculars in the constellation Aquarius in the dawn sky.
Below are some of the comets to keep a watch for in 2017 as they should be observable with small scopes and even binoculars.
Currently observable low in the evening at around magnitude 8 and will continue to brighten to magnitude 7 in January and then fade rapidly, including a approach to within 0.08AU of Earth on February 11th, as well as passing within a few degrees of globular cluster M3 shortly after.
Photo from January 6th.
C/2016 U1 ( NEOWISE )
Currently observable at magnitude 9 and predicted to brighten to magnitude 7 in mid January. Discovered on October 21, 2016. Not visible in the southern hemisphere.
C/2015 V2 ( Johnson )
Faint at magnitude 12, and will continue to brighten until mid 2017, with good chances of observation.
C/2015 ER61 ( PanSTARRS )
Should brighten to magnitude 7 spring of 2017, unfortunately not very visible to the northern latitudes. However it will cross many NGC and Messier objects throughout the first half of the year.
Expected to brighten to magnitude 6-7 around at the start of March, overall visible for about 45 days. For those in the northern hemisphere, best observations will be the end of February.
Expected to brighten to better than magnitude 6 in early April. A good opportunity for wide-field photo as it passes 5° of M92 at the end of April.
Photo from April 13th.
Seiichi Yoshida’s Bright Comet Listing (and future listing)
Paper by the British Astronomical Association
JunoCam onboard the Juno spacecraft is providing us with some great pictures of the Jupiter cloud top, but from the rarely seen polar angle. Pretty much all spacecrafts that have visited Jupiter did so with a fly by along the equatorial plane, which is also the same plane we observe Jupiter here on Earth. However with the Juno spacecraft, we now have a chance to enter into a polar orbit and take pictures of the polar regions.
Part of the reason behind JunoCam is to get the amateur astronomer community participating in selecting what parts of Jupiter the camera should be snapping pictures, and of processing the raw images. The image below was captured by JunoCam during Juno’s 3rd swing around Jupiter at a distance of about 37,000km. The south polar region is on the left.
NASA, JPL-Caltech, SwRI, MSSS; Processing: Damian Peach
The above was the PeriJove3 encounter (3rd pass), and voting on the next PeriJove4 will take place between January 19th and 23rd 2017. This is where the community can propose and vote for Points of Interest to photograph with JunoCam during the rather quick (2 hours) close pass with Juno. You can even submit images of Jupiter taken with your equipment to help plan the Points of Interest.
TIME magazine has released what their editors consider the best space photos of 2016.
P Crowther, University of Sheffield/NASA/ESA
Space-thriller themed mission trailer
Secrets lie deep within Jupiter, shrouded in the solar system’s strongest magnetic field and most lethal radiation belts. On July 4, 2016, NASA’s Juno spacecraft will plunge into uncharted territory, entering orbit around the gas giant and passing closer than any spacecraft before. Juno will see Jupiter for what it really is, but first it must pass the trial of orbit insertion. For more information: http://www.nasa.gov/juno and http://missionjuno.swri.edu
With Earth having passed between Jupiter and the Sun on March 8th, we have some of the finest observations of the Jovian planet. It’s only normal to have a few backyard astronomers setting their sights on the largest planet (myself included, still got unprocessed videos from March 27th). However Gerrit Kernbauer was lucky enough to record an unusual event: something slammed into Jupiter!
Phil Plait of Bad Astronomy reported that Gerrit Kernbauer with his 20cm telescope in Austria, captured on March 17th what appeared to be an impact of sort.
The issue was to confirm that it was an actual impact, and not some other natural effect or electronic noise in his setup. What better than to have a second independent observation, and that came from John McKeon with a 28cm telescope in Ireland.
Maybe I should go take a look at my videos on Jupiter from March 27th just in case… Actually with my 80mm telescope, I don’t think it would have picked up such an impact.
There’s a good article in Sky & Telescope on comets 252P/LINEAR and the smaller fragment P/2016 BA14, explaining observation opportunities. A comet hasn’t passed this close to Earth in 246 years. And as it does the wonderful green halo around 252P/LINEAR is sure to grow but will probably remain around magnitude 6.
As the comet flies by Earth it will sweep through the constellations quickly and then fade back to below magnitude 12 in short order. Therefore try not to miss it.