Universe Today

October 23, 2013December 23, 2015 by David Dickinson

Comet LINEAR Suddenly Brightens with Outburst: How to See It

Comet C/2012 X1 LINEAR as imaged by Howes, Guido & Nicolini on Monday, October 21st. (Credit: remanzacco.blogspot)

It’s swiftly becoming an “all comets, all the time” sort of observing season. The cyber-ink was barely dry on our “How to Spot Comet 2P/Encke” post this past Monday when we were alerted to another comet that is currently in the midst of a bright outburst.

That comet is C/2012 X1 LINEAR. Discovered on December 8^th, 2012 by the ongoing Lincoln Near Earth Asteroid Research (LINEAR) survey based in Socorro, New Mexico, Comet X1 LINEAR was expected to peak out at about +12^th magnitude in early 2014.

That all changed early this week, when amateur observers began to report a swift change in brightness for the otherwise nondescript comet. Japanese observer Hidetaka Sato reported the comet at magnitude +8.5 on October 20^th, a full 5.5 magnitudes above its expected brightness of +14. Remember, the magnitude scale is logarithmic, and the lower the number, the brighter the object. Also, 5 magnitudes represent an increase in brightness of 100-fold.

Astronomers Nick Howes, Martino Nicolini and Ernesto Guido used the remote 0.5 metre iTelescope based in New Mexico on the morning of Monday, October 21^st to confirm the outburst. Other amateurs and professional instruments are just now getting a look at the “new and improved” Comet X1 LINEAR low in the dawn sky. Romanian amateur observer Maximilian Teodorescu noted on yesterday’s Spaceweather that the comet was not visible through his 4.5 inch refractor, though it was easy enough to image.

Comet X1 LINEAR currently sits in the constellation Coma Berenices about mid-way between the stars Diadem, (Alpha Coma Berenices) and Beta Coma Berenices. Shining at +8.5 magnitude, the coma is about 85” across with a 10” bright central region. This gives X1 LINEAR the appearance of an unresolved +8^th magnitude globular cluster. In fact, a classic globular and a star party fave known as M3 lies about 8 degrees away at the junction of the constellations Canes Venatici, Boötes and Coma Berenices. M3 shines at +7^th magnitude and will make a great contrast on the hunt for the comet.

Unfortunately, the window of time to search for the comet is currently short. From latitude 30 degrees north, the comet sits only 15 degrees about the northeast horizon 30 minutes before local sunrise. The situation is a bit better for observers farther to the north, and mid-November sees the comet 20 degrees above the horizon in the dawn sky.

Comet X1 LINEAR is currently covering 40’ (2/3^rdsof a degree, or 1 1/3 the size of a Full Moon) a day, and will spend most of the month of November in the constellation Boötes. Keep in mind, X1 LINEAR is currently still on brightening trend “with a bullet.” Revised light curves now show it on track to reach magnitude +6 near perihelion early next year, but further brightening could still be in the cards for this one. Remember Comet 17P/Holmes a few years back? That one jumped from an uber-faint +17^th magnitude to a naked eye brightness of +2.8 in less than 48 hours.

Comet X1 LINEAR will reach a perihelion of 1.6 Astronomical Units (A.U.s) from the Sun on February 21st, 2014, and pass 1.6 A.U.s from the Earth around June 28^th, 2014. The comet has a high inclination of 44.4° degrees relative to the ecliptic, and is on a respectable 1872 year orbit.

Here are some notable dates for the comet through the end of 2013;

The path of Comet C/2012 X1 LINEAR from October 23 to November 28th. Click to enlarge. (Credit: Created using Starry Night Education Software).

-November 2^nd: Crosses into the constellation Boötes.

-November 6^th: Passes near the +4.9^th magnitude star 6 Boötis.

-November 16^th: Passes near the bright star Arcturus.

-December 6^th: Crosses into the constellation Serpens Caput.

-December 10^th: Passes near the +5 magnitude star Tau1 Serpentis.

-December 14^th: Comet X1 LINEAR sits only 8 degrees from Comet ISON.

-December 26^th: Crosses into the constellation Hercules.

Note: “Passes near” on the above list denotes a pass closer than one degree, except as noted.

Now, we REALLY need the Moon to pass Last Quarter phase this coming Saturday so we can get a good look at all of these dawn comets! As of writing this, the current scorecard of binocular comets— comets with a brightness between magnitude +6 and +10 —sits at:

-2P Encke: +7.9 magnitude in Leo.

-C/2013 R1 Lovejoy: +8.7^th magnitude in Canis Minor.

-C/2013 X1 LINEAR: +8.5^th magnitude in Coma Berenices.

-C/2012 S1 ISON: +9.7^th magnitude in Leo.

-C/2012 V2 LINEAR: +8.9^th magnitude in Centaurus.

Comet X1 LINEAR on the morning of October 25th, as seen from latitude 30 degrees north 45 minutes prior to sunrise. (Created using Stellarium).

It’s also amusing to note how the method of notification for these sorts of outbursts has changed in recent years. I first heard of the outburst of X1 LINEAR on Monday evening via Twitter. Contrast this with Comet Holmes in 2007, which came to our attention via message board RSS feed. And way back in 1983, we all read about of the close passage of Comet IRAS-Araki-Alcock… weeks after it occurred!

Another curious phenomenon may also work its way through the news cycle. When Comet Holmes became a hit back in 2007, spurious reports of comets brightening became fashionable. If you were to believe everything you read on the web, it suddenly seemed like every comet was undergoing an outburst! This sort of psychological trend towards wish fulfillment may come to pass again as interest in comet outbursts mounts.

It’s also worth noting that, contrary to rumors flying around ye’ ole web, Comet X1 LINEAR is not following Comet ISON. The two are on vastly different orbits, and only roughly lie along the same line of sight as seen from our Earthly vantage point.

The orbital path of Comet X1 LINEAR. (Credit: The JPL Solar System Dynamics Small-Body Database Browser). — The orbital path of Comet C/2012 X1 LINEAR. (Credit: The JPL Solar System Dynamics Small-Body Database Browser).

And that’s it for our weekly (daily?) segment of “As the Comets Turn…” don’t forget to “fall back” one hour and plan your morning comet-hunting vigil accordingly this coming Sunday if you live in Europe-UK. North America still has until November 3^rd to follow suit.

Happy comet hunting!

-Got a recent pic of Comet X1 LINEAR? be sure to post it in the Universe Today Flickr forum!

October 23, 2013December 23, 2015 by Jason Major

There Are Now Officially Over 1,000 Confirmed Exoplanets!

More than 1,000 exoplanets have been confirmed and cataloged (PHL @ UPR Arecibo)

It was just last week that we reported on the oh-so-close approach to 1,000 confirmed exoplanets discovered thus far, and now it’s official: the Extrasolar Planets Encyclopedia now includes more than 1,000! (1,010, to be exact.)

21 years after the first planets beyond our own Solar System were even confirmed to exist, it’s quite a milestone!

The milestone of 1,000 confirmed exoplanets was surpassed on October 22, 2013 after twenty-one years of discoveries. The long-established and well-known Extrasolar Planets Encyclopedia now lists 1,010 confirmed exoplanets.

Not all current exoplanet catalogs list the same numbers as this depends on their particular criteria. For example, the more recent NASA Exoplanet Archive lists just 919. Nevertheless, over 3,500 exoplanet candidates are waiting for confirmation.

The first confirmed exoplanets were discovered by the Arecibo Observatory in 1992. Two small planets were found around the remnants of a supernova explosion known as a pulsar. They were the surviving cores of former planets or newly formed bodies from the ashes of a dead star. This was followed by the discovery of exoplanets around sun-like stars in 1995 and the beginning of a new era of exoplanet hunting.

A "Periodic Table of Exoplanets" as listed by the Extrasolar Planets Encyclopedia (PHL) — A “Periodic Table of Exoplanets” as listed by the Extrasolar Planets Encyclopedia (PHL)

(The first exoplanets to be confirmed were two orbiting pulsar PSR B1257+12, 1,000 light-years away. A third was found in 2007.)

Exoplanet discoveries have been full of surprises from the outset. Nobody expected exoplanets around the remnants of a dead star (i.e. PSR 1257+12), nor Jupiter-size orbiting close to their stars (i.e. 51 Pegasi). We also know today of stellar systems packed with exoplanets (i.e. Kepler-11), around binary stars (i.e. Kepler-16), and with many potentially habitable exoplanets (i.e. Gliese 667C).

“The discovery of many worlds around others stars is a great achievement of science and technology. The work of scientists and engineers from many countries were necessary to achieve this difficult milestone. However, one thousand exoplanets in two decades is still a small fraction of those expected from the billions of stars in our galaxy. The next big goal is to better understand their properties, while detecting many new ones.”

– Prof. Abel Mendéz, Associate Professor of Physics and Astrobiology, UPR Arecibo

Source: Press release by Professor Abel Méndez at the Planetary Habitability Laboratory (PHL) at Arecibo

While not illustrating the full 1,010 lineup, this is still a mesmerizing visualization by Daniel Fabrycky of 885 planetary candidates in 361 systems as found by the Kepler mission. (I for one am looking forward to the third installment!)

Of course, scientists are still hunting for the “Holy Grail” of extrasolar planets: an Earth-sized, rocky world orbiting a Sun-like star within its habitable zone. But with new discoveries and confirmations happening almost every week, it’s now only a matter of time. Read more in this recent article by Universe Today writer David Dickinson.

October 23, 2013April 26, 2016 by Elizabeth Howell

Proposed Balloon Ride Would Let You See The Blackness Of Space

Artist's conception of World View's planned balloon mission some 19 miles (30 kilometers) up. Credit: World View Enterprises Inc.

Doesn’t that look fun? A startup company is proposing to send customers 19 miles (30 kilometers) into the air via balloon, where they can linger for two hours and look at the curvature of the Earth and experience a black sky. While it’s not high enough to qualify as a spaceflight, the listed ticket price may be a little more affordable for space enthusiasts: $75,000.

Don’t get too excited yet — the project appears to be in very early stages, and no “first flight” date is listed yet. But there are some interesting notes for those looking for space and science experience in the company.

Among the members of its executive is Alan Stern, the principal investigator for the New Horizons Pluto mission and NASA’s former associate administrator for the science mission directorate. (He’s also the CEO of the Golden Spike company that wants to offer commercial human missions to the moon.)
The executive also includes Jane Poynter and Taber MacCallum, who were both members of Biosphere 2. More recently, they also took on senior positions in Inspiration Mars, a Dennis Tito-led project that aims to send humans past Mars. (The target launch date for that is Jan. 5, 2018.)
The company proposing to build it is Paragon Space Development Corp. (which Poynter and MacCallum co-founded.) Paragon’s customers for thermal, environment and life support systems include a lot of name brands (including NASA). Paragon is also doing work for the Inspiration Mars project as well as Mars One, which aims to send colonists on a one-way trip to the Red Planet by 2023.

Artist's conception of World View's passenger capsule that will be carried aloft during a proposed balloon flight. Credit: World View Enterprises Inc. — Artist’s conception of World View’s passenger capsule that will be carried aloft during a proposed balloon flight. Credit: World View Enterprises Inc.

“Seeing the Earth hanging in the ink-black void of space will help people realize our connection to our home planet and to the universe around us, and will surely offer a transformative experience to our customers,” stated Poynter, who is CEO of World View. “It is also our goal to open up a whole new realm for exercising human curiosity, scientific research and education.”

World View’s announcement came after the Federal Aviation Administration “determined that World View’s spacecraft and its operations fall under the jurisdiction of the office of Commercial Space Flight,” the company added.

More information on their mission is available on the World View website. It’s a bit of a different track than Virgin Galactic and XCOR, who are offering rides into suborbital space for prices of $250,000 and $95,000, respectively. Neither company has an operational spacecraft yet, but they are in flight testing. Reports indicate they are hoping to get flights going next year.

October 22, 2013December 23, 2015 by Nancy Atkinson

Watch All Six Apollo Moon Landings at Once

So often, when we think of all the Apollo missions to the Moon, we recall the videos of the astronauts walking, jumping and driving around on the Moon. But the actual landing of the Lunar Module was such a key – if not nail-biting – part of the mission. Here in this video you can watch all six Apollo lunar landings at once. The footage uses the original descent camera coverage, realigned by the person who put this together —lunarmodule5 on YouTube — to 45 degrees to show what the lunar module pilots saw on the descent. There’s also the actual audio from all the landings. It’s amazing to hear both calm and anxiety in the voices of the LMP, Commander and Mission Control, as well as the jubilation after landing.

You can also watch all thirteen Saturn V launches at once in the video below — Apollo 4 thru Skylab with the Apollo 4 CBS audio added.

Best to go full-screen on these!

October 22, 2013December 23, 2015 by Nancy Atkinson

Astrophoto: Hubble in the Bubble

The Bubble Nebula, also known as NGC 7635, seen in the Hubble Palette. Credit and copyright: Terry Hancock.

Here’s a beautiful look at the Bubble Nebula, taken by astrophotographer Terry Hancock using what’s known as the “Hubble Palette,” — imaging in very narrow wavelengths of light using various filters. This allows very subtle details to be revealed, things that the human eye cannot see. Terry has been working on this one for a while — since mid-August — but the results are spectacular!

Terry took images from his “DownUnder Observatory” in Fremont, Michigan. He explains the image and techniques he used:

This last capture over 10 nights took me since mid-August 2013 to complete due to very high moisture in our West Michigan Skies right through this shoot. So, the data is therefore noisy and not the best but it is time to call it done for this year and move on! Due to poor conditions I had to use the H-Alpha data I had from my RGB+HA version using the QHY11 and combine with only one night capture using the QHY9 with it’s 3nm H-Alpha filter.

Using narrow band filters and post processed using the Hubble Palette technique the SII filter is assigned to Red, SII is assigned to Green and OIII is assigned to blue channel.

Total exposure time was 26 hours — persistence pays off! Thanks to Terry for sharing his gorgeous image!

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

October 22, 2013December 23, 2015 by Nancy Atkinson

Cosmonaut Sergei Krikalev, the World’s Most Prolific Time Traveler

Sergei Krikalev gives a thumbs up during suit check before the launch of STS-88 in 1998. Credit: NASA.

Is time travel a fact or is it just science fiction? Thanks to time dilation and Einstein’s theory of relativity, we know that time travel can and actually does happen, albeit only in extremely tiny increments at the speeds and distances we can travel in space. If you add up the accumulated speed cosmonaut Sergei Krivalev has traveled in space – the most of any human with a total time spent in orbit of 803 days 9 hours and 39 minutes – he has actually time-traveled into his own future by 0.02 seconds.

Time dilation is caused by differences in either gravity or relative velocity — each of which affects time in different ways. When astronauts and satellites orbit the Earth, they are slightly further away from the center of the planet –compared to people on the ground – and so they actually experience less gravitational time dilation. This means the astronauts’ time would run slightly faster, and when they return to Earth, they’d have to “come back” to the past compared to when they were in space.

But time dilation due to velocity means that clocks for astronauts in space run slightly slower relative to people who are on the ground. When you come back to Earth, you’d be have to go into the future slightly to catch up with clocks on the ground.

The effect of time dilation due to gravity, however, “is quite small because Earth’s gravity is quite weak,” says educator Colin Stuart in this great instructional video from TedEd, “and so the time dilation due to their speed wins out and astronauts really do travel a tiny amount into their futures.”

But, as stated earlier, with our current technology limiting the velocities of astronauts, these differences are minuscule: after 6 months on the ISS, an astronaut has aged less than those on Earth, but only by about 0.007 seconds. The effects would be greater if we could get the ISS to orbit Earth at near the speed of light (approximately 300,000 km/s), instead of the actual speed of about 7.7 km/s.

This effect has been proven by GPS satellites, which orbit Earth at about 14,000 km/h (9,000 mph) which cuts several microseconds off their clocks daily, relative to clocks on Earth.

Watch the video for more information and see associated material from TedEd, or read these interesting articles from Huffington Post and DailyMail. Here are some calculations about time and the “Twin Paradox.”

And if you really want to know what time it is, check out the website for the primary atomic clock.

October 22, 2013December 23, 2015 by Ken Kremer

Cygnus Commercial Cargo Craft Completes Historic First Flight to Space Station

The Cygnus commercial resupply craft departed the ISS this morning (Oct. 22) to complete its maiden voyage after being released from Canadarm2 by station astronauts. Credit: NASA TV

Commercial space took another major leap forward this morning, Oct 22., when the privately developed Cygnus cargo vehicle undocked from the International Space Station on its historic maiden flight and successfully completed a highly productive month long stay during its demonstration mission – mostly amidst the US government shutdown.

The Cygnus was maneuvered about 10 meters (30 feet) away from the station and held in the steady grip of the stations fully extended robotic arm when astronauts Karen Nyberg and Luca Parmitano unlatched the arm and released the ship into free space at 7:31 a.m. EDT today – signifying an end to joint flight operations.

The next Cygnus resupply vessel is due to blast off in mid-December and is already loaded with new science experiments for microgravity research and assorted gear and provisions.

After the Expedition 37 crew members quickly pulled the arm back to a distance 1.5 meters away from Cygnus, ground controllers issued a planned “abort” command to fire the ships thrusters and safely depart from the massive orbiting lab complex.

Space Station robotic arm releases Cygnus after detachment from the ISS Harmony node. Credit: NASA TV

“It’s been a great mission. Nice work today!” radioed Houston Mission Control at NASA’s Johnson Space Center.

The vehicles were flying over the Atlantic Ocean and off the east coast of Argentina as Cygnus left the station some 250 miles (400 km) overhead in low Earth orbit.

The event was carried live on NASA TV and Cygnus was seen moving rapidly away.

Barely five minutes later Cygnus was already 200 meters away, appeared very small in the cameras view and exited the imaginary “Keep Out Sphere” – a strictly designated safety zone around the million pound station.

Cygnus commercial cargo craft rapidly departed the ISS this morning (Oct. 22) after release from the Canadarm2 robotic arm. Station modules visible at bottom. Credit: NASA TV

The Cygnus resupply ship delivered about 1,300 pounds (589 kilograms) of cargo, including food, clothing, water, science experiments, spare parts and gear to the six person Expedition 37 crew.

After the crew unloaded all that cargo, they packed the ship with 2,850 pounds of no longer needed trash.

On Wednesday (Oct. 23), a pair of deorbit burns with target Cygnus for a destructive reentry back into the Earth’s atmosphere at 2:18 p.m. EDT, to plummet harmlessly into the Pacific Ocean.

Cygnus was developed by Orbital Sciences Corp. with seed money from NASA in a public-private partnership between NASA and Orbital Sciences under NASA’s COTS commercial transportation initiative.

SpaceX Corp. was also awarded a COTS contract to develop the Dragon cargo carrier so that NASA would have a dual capability to stock up the station.

COTS was aimed at fostering the development of America’s commercial space industry to deliver critical and essential supplies to the ISS following the retirement of the Space Shuttle program.

“Congratulations to the teams at Orbital Sciences and NASA who worked hard to make this demonstration mission to the International Space Station an overwhelming success,” NASA Administrator Charles Bolden said in a statement.

Antares rocket lifts off at 10:58 a.m. EDT Sept 18 with commercial Cygnus cargo resupply ship bound for the International Space Station (ISS) from Mid-Atlantic Regional Spaceport Pad-0A at NASA’s Wallops Flight Facility in Virginia. Credit: Ken Kremer (kenkremer.com)

“We are delighted to now have two American companies able to resupply the station. U.S. innovation and inspiration have once again shown their great strength in the design and operation of a new generation of vehicles to carry cargo to our laboratory in space. Orbital’s success today is helping make NASA’s future exploration to farther destinations possible.”

America completely lost its capability to send humans and cargo to the ISS when NASA’s space shuttles were forcibly retired in 2011. Orbital Sciences and SpaceX were awarded NASA contracts worth over $3 Billion to restore the unmanned cargo resupply capability over 20 flights totally.

Cygnus was launched to orbit on its inaugural flight on Sept. 18 atop Orbital’s commercial Antares rocket from NASA’s Wallops Flight Facility on the Eastern shore of Virginia.

The initially planned Sept. 22 berthing of the spacecraft at a port on the Earth facing Harmony node was delayed a week to Sept. 29 due to an easily fixed communications glitch. It was no worse for the wear and performed admirably.

“Antares next flight is scheduled for mid December,” according to Frank Culbertson, former astronaut and now Orbital’s executive Vice President responsible for the Antares and Cygnus programs.

Ken Kremer

After launching to orbit atop the Antares rocket on Sept. 18, the first ever Cygnus cargo spacecraft is chasing the ISS and set to dock on Sept 22. Until then you may be able to track it in the night skies. Here is full scale, high fidelity mockup of Cygnus to give a feel for its size being similar to a small room. Credit: Ken Kremer (kenkremer.com) — After launching to orbit atop the Antares rocket on Sept. 18, the first ever Cygnus cargo spacecraft chased the ISS and docked on Sept 29. Here is full scale, high fidelity mockup of Cygnus to give a feel for its size being similar to a small room. Credit: Ken Kremer (kenkremer.com)

October 22, 2013December 23, 2015 by Elizabeth Howell

A Colorful Art Project You Can Only Do In Space

On Expedition 27 in May 2011, NASA astronaut Cady Coleman participated in the Auroral Oval Spiral Top experiment. Credit: NASA

Wow! That was our reaction to seeing this picture (and others) of a light show aboard the International Space Station. After confirming with NASA that the images circulating lately on social media are real, we were directed to the Japan Aerospace Exploration Agency (JAXA), who co-ordinated this experiment.

The work is called “Auroral Oval Spiral Top” and was done in the Kibo module on May 12, 2011, JAXA said. This was the second version of the experiment, which initially ran April 30, 2009 during Expedition 19.

Spiral Top performed in 2009. The art project was an earlier version of the Auroral Oval Spiral Top experiment that was done in May 2011. Credit: NASA/JAXA

“Auroral Oval Spiral Top uses a spinning top that has arms illuminating with LED linear light sources and point light sources. Various movements of the spinning top floating in microgravity show aurora-like light traces,” JAXA stated on a web page about the experiment.

The project, JAXA added, is “designed to produce aurora-like luminescence traces using a spinning top with both linear and point light sources. In microgravity, the center of gravity of the spinning top continuously and randomly moves while it is spinning. Using the characteristics of the top in microgravity, the project tries to produce various light arts using its unexpected movements/spins, by changing attaching locations of its arms and weights.”

Takuro Osaka, a professor at the University of Tsukuba, was the principal investigator of this art project. What are your favorite experiments performed by astronauts in space? Let us know in the comments.

Another view of the Auroral Oval Spiral Top experiment. Credit: NASA

October 21, 2013December 28, 2015 by Fraser Cain

Astronomy Cast 318: Escape Velocity

Sometimes you’ve just got to get away from it all. From your planet, your Solar System and your galaxy. If you’re looking to escape, you’ll need to know just what velocity it’ll take to break the surly bonds of gravity and punch the sky.

Visit the Astronomy Cast Page to subscribe to the audio podcast!

We record Astronomy Cast as a live Google+ Hangout on Air every Monday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.

October 21, 2013December 23, 2015 by David Dickinson

How to See This Season’s “Other” Comet: 2P/Encke

Comet 2P/Encke as imaged by Damian Peach on October 12th. (Credit: D. Peach)

2013 may well go down as “The Year of the Comet.” After over a decade punctuated by only sporadic bright comets such as 17P/Holmes, C/2011 W3 Lovejoy and C/2006 P1 McNaught, we’ve already had two naked eye comets visible this year by way of C/2012 F6 Lemmon and C/2011 L4 PanSTARRS. And of course, all eyes are on Comet C/2012 S1 ISON as it plunges towards perihelion on U.S. Thanksgiving Day, November 28^th.

But there’s an “old faithful” of comets that’s currently in our solar neighborhood, and worth checking out as well. Comet 2P/Encke (pronounced EN-key) currently shines at magnitude +7.9 and is crossing from the constellation Leo Minor into Leo this week. In fact, Encke is currently 2 magnitudes— over 6 times brighter than Comet ISON —and is currently the brightest comet in our skies. Encke is expected to top out at magnitude +7 right around perihelion towards the end of November. Encke will be a fine binocular object over the next month, and once the Moon passes Last Quarter phase on October 26^th we’ll once again have a good three week window for pre-dawn comet hunting. Comet Encke made its closest pass of the Earth for this orbit on October 17^th at 0.48 Astronomical Units (A.U.s) distant. This month sees its closest passage to the Earth since 2003, and the comet won’t pass closer until July 11^th, 2030.

The orbital path of Comet 2P/Encke. (Credit: The NASA/JPL Solar System Dynamics Small-Body Database Browser).

This will be Comet Encke’s 62^nd observed perihelion passage since its discovery by Pierre Méchain in 1786. Encke has the shortest orbit of any known periodic comet, at just 3.3 years. About every 33 years we get a favorable close pass of the comet, as last occurred in 1997, and will next occur in 2030.

But this year’s apparition of Comet Encke is especially favorable for northern hemisphere observers. This is due to its relatively high orbital inclination angle of 11.8 degrees and its passage through the morning skies from north of both the ecliptic and the celestial equator. Encke is about half an A.U. ahead of us in our orbit this month, crossing roughly perpendicular to our line of sight.

Note that Encke is also running nearly parallel to Comet ISON from our vantage point as they both make the plunge through the constellation Virgo into next month. Mark your calendars: both ISON and Encke will fit into a telescopic wide field of view around November 24^th in the early dawn. Photo-op!

Here are some key dates to help you in your morning quest for Comet Encke over the next month:

-October 22^nd: Crosses into the constellation Leo.

-October 24^th: Passes near the +5.3 magnitude star 92 Leonis.

-October 25^th: Passes near the +4.5 magnitude star 93 Leonis.

-October 27^th: Passes briefly into the constellation Coma Berenices.

-October 29^th: Passes near the +11^th magnitude galaxy M98, and crosses into the constellation Virgo.

-October 30^th: Passes near the +10^th magnitude galaxy pair of M84 & M86.

2P Encke from 20 Oct to 20 Nov (Created using Starry Night Education Software). — The celestial path of Comet 2P/Encke from October 20th to 20 November 20th. Note that ISON is very near Encke on the final date. Click on the image to enlarge. (Created using Starry Night Education Software).

-November 2^nd: Passes between the two +5^th magnitude stars of 31 and 32 Virginis.

-November 3^rd: A hybrid solar eclipse occurs across the Atlantic and central Africa. It may just be possible to spot comet Encke with binoculars during the brief moments of totality.

-November 4^th: Passes near the +3.4 magnitude star Auva (Delta Virginis).

-November 7^th: Crosses from north to south over the celestial equator.

-November 11^th: Passes near the +5.7^th star 80 Virginis.

-November 17^th: The Moon reaches Full, and enters into the morning sky.

-November 18^th: Passes 0.02 A.U. (just under 3 million kilometers, or 7.8 Earth-Moon distances) from the planet Mercury. A good chance for NASA’s Messenger spacecraft to perhaps snap a pic of the comet?

-November 19^th: Passes 1.5 degrees from Mercury and crosses into the constellation Libra.

-November 20^th: Crosses to the south of the ecliptic plane.

-November 21^st: Reaches perihelion, at 0.33 AU from the Sun.

-November 24^th: Comet Encke passes just 1.25 degrees from Comet ISON. Both will have a western elongation of 15 degrees from the Sun.

-November 26^th: Passes near the +4.5 magnitude star Iota Librae and the +6th magnitude star 25 Librae.

-December 1^st: Crosses into the constellation Scorpius.

-December 5^th: Enters into view of SOHO’s LASCO C3 camera.

Note: “Passes near” on the above list indicates a passage of Comet Encke less than one angular degree (about twice the size of a Full Moon) from an interesting object, except where noted otherwise.

Binoculars are your best bet for catching sight of Comet 2P/Encke. For middle northern latitude observers, Comet Encke reaches an elevation above 20 degrees from the horizon about two hours before local sunrise. Keep in mind, Europe and the U.K. “fall back” an hour to Standard Time this coming weekend on October 27^th, and most of North America follows suit on November 3^rd, pushing the morning comet vigil back an hour as well.

Two other comets are both currently brighter than ISON and also merit searching for: Comet C/2013 R1 Lovejoy, at +8.7^th magnitude in Canis Minor, and Comet C/2012 X1 LINEAR, currently also in Coma Berenices and undergoing a minor outburst at magnitude +8.5.

Be sure to check these celestial wonders out as we prepare for the “Main Event” of Comet ISON in November 2013!