Closest Comet in 246 Years

Status

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.

Comets to Pass Near Earth

Status

Two comets will pass near Earth between March 21st and 23rd. Comets 252P/LINEAR and P/2016 BA14 will pass between 14 and 9 lunar orbits with the Earth.  As both comets  have similar orbits they most likely broke in two following a close encounter with a planet’s gravity.

252P/LINEAR  has surprised everyone by brightening to magnitude 6 as it was predicted to remain in the 12-14 range.  Presently accessible to folks in the southern hemisphere it will be visible to northern observers after the Earth fly-by.

Comet C/2013 US10 (Catalina) Continues To Be Visible

Comet C/2013 US10 (Catalina) continues to be visible at around magnitude 6 to observers in the southern hemisphere.  For people north of the equator, we’ll have to wait until late November when it will become an early morning comet.

One date to mark on your calendar is the morning of December 7th.  A wonderful early morning opportunity to spot C/2013 US10 next to Venus and a Lunar crescent all within a 6 deg window.  This will be fairly low (20 deg) over the South-East horizon.

Comet C/2013 US10 Catalina, Venus and the Moon

Comet C/2013 US10 Catalina, Venus and the Moon

Under dark skies it should be observable to the naked eye.  But binoculars or even a camera zoom lens will provide for better observation.

Bright Comet C/2013 US10 (Catalina) – Visible to Northern Hemisphere end of November

There’s a bright comet in the sky, currently at magnitude 6 and predicted to brighten to 5 by November. Not yet visible in the Northern Hemisphere, but just as it peaks in brightness towards the end of November, it will start showing up in the early morning sky, gradually rising earlier every day until late January 2016

Note that a good opportunity will be around January 2nd when it will pass within 1deg of magnitude 0 star Alpha Bootis – Arcturus.  Until then, people in the south keep enjoying it, I’ll just have to wait for the cold winter nights to get a peek at this comet.

Comet C/2013 US10 is not periodic, but comes from the distant Oort Cloud and this will be it’s only recorded passage by the Sun.   After spending millions of years slowly orbiting the outer solar reaches, it got disturbed, possibly by a nearby star and is now on an ejection trajectory; its velocity is such that it will be flung into interstellar space, away from the Sun’s influence until it’s picked up by another star.

Trajectory of Comet C/2013 US10 Catalina for 2015-2016

Trajectory of Comet C/2013 US10 Catalina for 2015-2016

 

Visibility of Comet C/2013 US10 Catalina in the Evening

Visibility of Comet C/2013 US10 Catalina in the Evening

Visibility of Comet C/2013 US10 Catalina in the Early Morning

Visibility of Comet C/2013 US10 Catalina in the Early Morning

Comet 67P/Churyumov–Gerasimenko : Where is it, and where will it be.

In my previous post I’ve mentions that coment 67P/Churyumov–Gerasimenko is currently between the orbits of Jupiter and Mars, on a trip towards the Sun.  While some comets take decades to become visible again this one has an orbital period of 6.44 years, therefore a frequent visitor.  That was one of the selection criteria for the target comet: short orbital period such that it did not take too much fuel or planetary gravity assist to intercept.

On August 13th it will be at it’s closest position to the sun (perihelion), therefore brightest and a good time to observe.  Afterwards it will be swinging back out towards Jupiter on its elongated orbit.  For people in the Northern Hemisphere, the best time to observe comet 67P will be after this August date.  Below is a chart showing that the comet will be visible in the early morning starting in June 2015, and will be visible at higher altitudes in the sky throughout the following months.

Comet 67P visibility for around 45 Latitude N.

Comet 67P visibility for around 45 Latitude N.

Below is a chart (click to enlarge) showing the position of 67P until November 15th.

Comet 67P/Churyumov–Gerasimenko sky chart for Nov 2014 to Nov 2015

Comet 67P/Churyumov–Gerasimenko sky chart for Nov 2014 to Nov 201

A good photographic opportunity will be August 8th when comet 67P will pass right under open cluster M35.

Comet 67P passing under Open Cluster M35

Comet 67P passing under Open Cluster M35

Graphics generated with C2A Planetarium Software

Comet 67P/Churyumov–Gerasimenko – Can we see it?

First of all I want to congratulate the Rosetta team on their successful landing of Philae on the comet surface.  When you consider that the spacecraft was launched 10 years ago, it was essentially designed and assembled with 15-year-old technology.  Back then, digital cameras were just entering the market and the Palm III PDA was the mobile device everyone wanted.  In fact, much of the code running on Rosetta and Philae was developed after the aircraft was launched.

Presently 67P is located between Jupiter and Mars, on its swing towards the sun. To give you an idea how far out it’s located in the solar system, it takes over 28 minutes for radio communications from Rosetta to reach Earth.  Therefore if mission control sends a comment to Rosetta, the results are only known one hour later!

Location of comet 67P/Churyumov–Gerasimenko on November 13th, 2014

Location of comet 67P/Churyumov–Gerasimenko on November 13th, 2014 (Credit: ESA)

Starting in May 2015 67P will become visible to observers in the Northern Hemisphere, and will gradually brighten until achieving perihelion on August 13, 2015.  Because it does not venture very close to the sun, past observations indicate that it will only reach magnitude 11 at best; a challenge to backyard telescopes.

Better slew your observation by 9 degrees north, that’s where comet 141P/Machholz will be in the same constellation (Gemini) and at magnitude 8; a slightly brighter target.  And if you have no luck observing either comets or capturing them on photo, open cluster M35 is in the area.

Until then, you can follow Rosetta and Philae’s adventure on their blog: blogs.esa.int/rosetta/

Mars and Comet Siding Spring – Chance of a lifetime

NASA/JPL-Caltech

NASA/JPL-Caltech

On October 19th a once in a lifetime event will happen.  Comet Siding Spring (C/2013 A1) will pass very close to Mars, one tenth the distance of the closest Earth-comet pass.  While there is no chance of impact, NASA has moved some of its Mars orbiting satellite to be behind the planet is it passes through the comet’s dust tail in order to protect the equipment.

At predicted magnitude 11, it will be limited to large telescopes with camera or CCD.  But its close proximity to Mars will make it an easy target to locate.  Unfortunately for North America, the closest approach will take place 2:28pm EDT.

Luckily NASA has setup as dedicate web site leading up to and after the even publish information and photos.  The SLOOH telescope will also have a live webcast.