Venus Archives

May 5, 2014December 23, 2015 by David Dickinson

Comet Jacques Brightens: How to See it in May

Comet Jacques as imaged on March 18th, shortly after discovery. Credit: Efrain Morales Rivera.

A recently discovered comet is headed northward and is set to put on one of two fine performances for binocular observers in 2014 starting this week.

Comet C/2014 E2 Jacques was discovered on March 13^th 2014 by Cristóvão Jacques, Eduardo Pimentel and João Ribeiro de Barros while observing from the Southern Observatory for Near Earth Asteroids Research (SONEAR) facility located near Oliveira, Brazil.

The comet was just about at +15^th magnitude at the time of discovery as it glided across the southern hemisphere constellation of Centaurus.

While a majority of comet discoveries are destined to remain small and faint, Comet Jacques was immediately shown to be something special. Upon discovery of any new comet, the first task is to gain several observations hours or nights apart to accurately gauge its distance and orbit. Are astronomers looking at a small, garden variety comet close up, or a large, active one far away?

In the case of Comet Jacques, it was something in between: a comet about 1.22 Astronomical Units (A.U.s) distant at time of discovery. Comet Jacques is headed towards perihelion 0.66 A.U. from the Sun in early July and will pass 0.56 A.U. from Earth on August 28th. Follow up observations carried out using the iTelescope at Siding Spring Australia showed a slightly elongated coma about 2 arc minutes across shortly after discovery, and the comet has recently jumped up to magnitude +8 — ahead of the projected light curve — in just the past week.

The path of Comet Jacques, looking west from latitude 30 degree north 45 minutes after sunset. Credit: Starry Night.

We caught our first good look at Comet Jacques last night while setting up for the Virtual Star Party. While +10 magnitude or brighter is usually a pretty good rule of thumb for binocular visibility, we found that the comet was only apparent as a fuzzy smudge viewing it with a 8” Schmidt-Cassegrain telescope using averted vision at low power. Remember, the brightness of a comet is spread out over its apparent surface area, similar to viewing a diffuse nebula. Our first telescopic views of the ill-fated comet ISON as it breeched +10^th magnitude were similar. Certainly, a nearby waxing crescent Moon in Gemini last night didn’t help.

How bright will Comet Jacques get? Current projections call for it to perhaps break naked eye visibility around +6^th magnitude after June 1^st and reach as bright as +4^th magnitude in early July near perihelion. After its first evening act in May and June, Comet Jacques will reemerge in the dawn sky for northern hemisphere observers for Act 2 and trace a path northward paralleling the galactic plane through the star rich fields of Perseus, Cassiopeia, Cepheus and Cygnus in August and September of this year. If our luck holds out, Comet Jacques will remain above 6^th magnitude until early September.

Credit JPL — The path of Comet Jacques through the inner solar system. Credit: JPL solar system small body generator.

This comet also created a brief flurry of interest when it was revealed that it will pass just 0.085 AUs or 12,700,000 kilometers from Venus on July 13^th, 2014. Though close, this is still 31 times the distance from Earth to the Moon. The only “eyes” that humanity has currently in operation around Venus is ESA’s Venus Express orbiter. During closest approach Comet Jacques will appear just over 3 degrees away from Venus as seen from our Earthly vantage point.

Another comet is also set to photobomb a planet, as Comet A1 Siding Spring passes a nominal distance of 0.0009 A.U.s or 135,000 kilometers from Mars this Fall on October 19th.

The closest recorded passage of a comet near Earth was Comet D/1770 L1 Lexell in 1770, which passed us 0.015 A.U.s or 233 million kilometres distant.

Now on to Act 1. May finds Comet Jacques spending most of the month in the long rambling constellation of Monoceros. Currently moving just under 2 degrees a day, Comet Jacques crosses the celestial equator northward this week on May 8^th. You’ll note its high orbital inclination of 156.4 degrees as it speeds northward. Comet Jacques has a long orbital period gauged at over 30,000 years — the last time Comet Jacques visited the inner solar system, our ancestors had the Last Glacial Maximum period to look forward to.

Light curve — The projected light curve of comet Jacques with recent observations. Credit: Seiichi Yoshida/aerith.net.

Comet Jacques is currently the brightest comet “with a bullet,” edging out the +9^th magnitude comets C/2012 K1 PanSTARRS gilding through Canes Venatici and comet C/2012 X1 LINEAR, currently residing in the constellation of Aquila the Eagle. A great place to keep up with current observations of comets is the Comet Observation Database. We’re also pinging the IAU Minor Planet Center’s quick look page for new discoveries daily.

Here are some highlights to watch out for as Comet Jacques heads towards perihelion. Passages within one degree — twice the size of the Full Moon — near stars brighter than +5^th magnitude are noted unless mentioned otherwise:

The celestial path of Comet Jacques from May 3rd through June 1st. Credit: Starry Night.

May 8^th: Passes the +4.1 magnitude star Delta Monocerotis and crosses north of the celestial equator.

May 10^th: Passes planetary nebula NGC 2346.

May 11^th: Passes briefly into Canis Minor before reentering the constellation Monoceros.

May 14^th: Full Moon occurs, marking the start of a favorable two week period of moonless evenings soon after.

May 24^th: Passes the +4.8 magnitude star 17 Monocerotis.

May 28^th: New Moon occurs, marking the return of the Moon to early evening skies.

May 29^th: Passes the +4.7 magnitude star 15 Monocerotis.

May 30^th: Passes the Christmas tree cluster. Photo op!

May 31^st: The waxing crescent Moon passes less than 8 degrees from Comet Jacques.

June 1^st: Comet Jacques reaches naked eye visibility?

June 6^th: Crosses into the constellation Gemini.

June 11^th: Crosses into the constellation Taurus.

June 13^th: Full Moon occurs.

June 14^th:Crosses the galactic plane.

June 21^st: Passes into the field of view of SOHO’s LASCO C3 camera.

June 27^th: New Moon occurs.

July 2^nd: Reaches perihelion at 0.6638 A.U. from the Sun.

July 8^th: Crosses north of the ecliptic plane.

July 13^th: Passes 0.085 A.U. from Venus.

August 28^th: Passes 0.56 A.U. from Earth.

And thus, Comet Jacques joins the parade of fine binocular comets in the 2014 night sky, as the stage is set for Act 2 this fall. And keep in mind, the next “big one” could grace our skies at anytime… more to come!

April 10, 2014December 23, 2015 by David Dickinson

Two Observing Challenges: Catch Venus Passing Neptune And Occulting a Bright Star

The Milky Way, The Large and Small Magellanic Clouds, Zodiacal Light, and Venus as seen from the Karoo Desert in South Africa early this month. Credit: Cory Schmitz.

Have you been following the planet Venus this season? 2014 sees the brightest planet in our Earthly skies spend a majority of its time in the dawn. Shining at magnitude -3.8, it’s hard to miss in the morning twilight. But dazzling Venus is visiting two unique celestial objects over the next week, and both present unique observing challenges for the seasoned observer.

First up is an interesting close conjunction of the planets Venus and Neptune on the morning of Saturday, April 12^th. Closest conjunction occurs at 3:00 Universal Time (UT) April 12th favoring Eastern Europe, the Middle East and eastern Africa, when the two worlds appear to be just 40 arc minutes apart, a little over – by about 10’ – the apparent size of a full Moon. Shining at magnitude +7.8 and 30,000 times fainter than Venus, you’ll need a telescope to tease out Neptune from the pre-dawn sky. Both objects will, however, easily fit in a one degree field of view, in addition to a scattering of other stars.

Looking to the east the morning of April 12th from the U.S. East Coast near latitude 30 degrees north. Nearby stars are annotated in red by magnitude with decimals omitted. Created using Stellarium, click to enlarge.

At low power, Venus will display a 59% illuminated gibbous phase 20” across on the morning of the 12^th, while Neptune will show a tiny disk barely 2” across. Still, this represents the first chance for viewers to recover Neptune since solar conjunction behind the Sun on February 23^rd, 2014, using dazzling Venus as a guide.

Both sit 45 degrees west of the Sun and currently rise around 3 to 4 AM local dependent on latitude.

This is one of the closest planet-planet conjunctions for 2014. The closest is Venus and Jupiter at just 0.2 degrees apart on August 18^th. This will represent the brightest planet versus planet conjunction for the year, and is sure to illicit multiple “what’s those two bright stars in the sky?” queries from morning commuters… hopefully, such sightings won’t result in any border skirmishes worldwide.

Now, for the mandatory Wow factor. On the date of conjunction, Earth-sized Venus is 0.84 Astronomical Units (A.U.s) or over 130 million kilometres distant. Ice giant Neptune, however, is 30.7 AUs or 36 times as distant, and only appears tiny though it’s almost four times larger in diameter. Sunlight reflected from Venus takes 7 minutes to reach Earth, but over four hours to arrive from Neptune. We’ve visited Venus lots, and the Russians have even landed there and returned images from its smoldering surface, but we’ve only visited Neptune once, during a brief flyby of Voyager 2 in 1989.

From Neptune looking back on April 12th, Earth and Venus would appear less than 1 arc minute apart…. though they’d also be just over one degree from the Sun!

The "shadow path" of the occultation of Lambda Aquarii by Venus on April 16th. Credit: IOTA/Steve Preston/www.asteroidoccultation/Occult 4.0. — The “shadow path” of the occultation of Lambda Aquarii by Venus on April 16th. Credit: IOTA/Steve Preston/www.asteroidoccultation/Occult 4.0.

But an even more bizarre event happens a few days later on April 16^th, though only a small region of the world in the South Pacific may bare witness to it.

Next Wednesday from 17:59 to 18:13 UT Venus occults the +3.7 magnitude star HIP 112961 also known as Lambda Aquarii on the morning of April 16^th 2014.

Venus will be a 61% illuminated gibbous phase 19” in diameter. Unfortunately, although North America is rotated towards the event, it’s also in the middle of the day.

The best prospects to observe the occultation are from New Zealand and western Pacific at dawn. The star will disappear behind the bright limb of Venus in dawn twilight before emerging on its dark limb 5 minutes later as seen from New Zealand.

Note: New Zealand switched back to standard time on April 6^th – it’s currently Fall down under – and local sunrise occurs around ~7:40 AM.

Lambda Aquarii is a 3.6 solar mass star located 390 light years distant. As far as we know, it’s a solitary star, though there’s always a chance that a companion could make itself known as it emerges on the dark limb of Venus. Such an observation will, however, be extremely difficult, as Venus is still over 700 times brighter than the star!

North Americans get to see the pair only 20’ apart on the morning of the 12^th.

And further occultation adventures await Venus in the 21^st century. On October 1^st, 2044 it will occult Regulus… and on November 22^nd, 2065 it will actually occult Jupiter!

Such pairings give us a chance to image Venus with a “pseudo-moon.” Early telescopic observers made numerous sightings of a supposed Moon of Venus, and the hypothetical object even merited the name Neith for a brief time. Such sightings were most likely spurious internal reflections due to poor optics or nearby stars, but its fun to wonder what those observers of old might’ve seen.

… and speaking of moons, don’t miss a chance to see Venus near the daytime Moon April 25^th. Follow us as @Astroguyz on Twitter as we give shout outs to these and other strange pairings daily!

March 15, 2014December 23, 2015 by Bob King

New Comet Jacques May Pass 8.4 million miles from Venus this July

Comet C/2014 E2 Jacques photographed from Siding Spring Observatory on March 14, 2014. Credit: Rolando Ligustri

Congratulations to Cristovao Jacques and the SONEAR team! On March 13 they snared C/2014 E2 (Jacques) in CCD images taken with a 0.45-meter (17.7-inch) wide-field reflector at the SONEAR (Southern Observatory for Near Earth Asteroids Research) observatory near Oliveira, Brazil. A very preliminary orbit indicates its closest approach to the sun will occur on June 29 at a distance of 56 million miles followed two weeks later by a relatively close flyby of Venus of 0.09 a.u. or 8.4 million miles (13.5 million km). If a comet approached Earth this closely so soon after perihelion, it would be a magnificent sight. Of course, watching from Venus isn’t recommended. Even if we could withstand its extreme heat and pressure cooker atmosphere, the planet’s perpetual cloud cover guarantees overcast skies 24/7.

Comet Jacques travels across the deep southern sky in early spring as seen from mid-northern latitudes. Approximate positions are shown through April 4. Stellarium

It’s the team’s second comet discovery this year after turning up C/2014 A4 (SONEAR) in January. Comet Jacques has been tracking across northern Centaurus since discovery. Over the next few nights, it straddles the border with Hydra where it will be visible low in the southern sky around for northern hemisphere observers from about midnight to 2 a.m. If you live on a Caribbean island and points south your view will be even better.

Steven Tilley’s animation of Comet C/2014 E2 Jacques over 35 minutes on March 13, 2014

Comet Jacques exhibits a dense, fairly bright 2-arc-minute coma or cometary atmosphere with a short northward-pointing tail. Brightness estimates have been hard to come by, but it appears the comet may be around magnitude +11.5 – 12 or within range of an 8-inch (20-cm) or larger telescope. One thing’s for certain. In the coming weeks, E2 will be approaching both the Earth and the sun and brightening as it slowly gains altitude in the evening sky.

Another view of the comet on March 13 through a 0.5-meter (19.5-inch) telescope. Credit: Ernesto Guido, Nick Howes, Martino Nicolini

Shortly after perihelion, Comet Jacques will shine brightest at around magnitude +10-10.5 (though it could be brighter) and remain nearly this bright as it swings north from Orion into Perseus from mid-July to mid- August. Closest approach to Earth occurs on Aug. 29-30 at 54 million miles (87 million km). It will join Comet Oukameiden – predicted to reach binocular visibility in late August – to offer comet lovers much to look forward to as the summer wanes.

March 11, 2014December 23, 2015 by Nancy Atkinson

‘Rainbow’ on Venus Seen for First Time

False colour composite of a rainbow-like feature known as a ‘glory’, seen on Venus on 24 July 2011. The image is composed of three images at ultraviolet, visible, and near-infrared wavelengths from the Venus Monitoring Camera. The images were taken 10 seconds apart and, due to the motion of the spacecraft, do not overlap perfectly. The glory is 1200 km across, as seen from the spacecraft, 6000 km away. It's the only glory ever seen on another planet. Credit: ESA/MPS/DLR/IDA.

Oh glory! A rainbow-like optical phenomenon known as a ‘glory’ has been imaged for the first time on another planet. It was seen in the atmosphere of our nearest neighbor, Venus by ESA’s Venus Express orbiter.

Rainbows and glories occur when sunlight shines on cloud droplets. While rainbows arch across the sky, glories appear as circular rings of colored concentric rings centered on a bright core.

Glory with aircraft shadow in the center. Via Wikimedia Commons.

Glories are only seen when the observer is situated directly between the Sun and the cloud particles that are reflecting sunlight. On Earth, they can often be seen with the naked eye from airplanes, or when looking down upon fog or water vapor, such as when climbing a mountain.

On Earth, the simple ingredients needed for a rainbow are sunlight and raindrops. On Venus, the droplets are likely made of sulfuric acid.

Three images showing the glory at ultraviolet (left,) visible (centre) and near-infrared (right) wavelengths as taken by the Venus Monitoring Camera. The feature was observed on 24 July 2011 and measures 1,200 km across, as seen from the spacecraft, 6,000 km away. Credit: ESA/MPS/DLR/IDA.

Seeing this glory was no accident: they made a calculated effort to image the clouds with the Sun directly behind the Venus Express spacecraft. The scientists were hoping to spot a glory in order to determine important characteristics of the cloud droplets.

Today, the team reported that they were successful. The glory in the images here was seen at the Venus cloud tops, 70 km above the planet’s surface, back on July 24, 2011. Their paper was just recently accepted for publication.

The glory was 1,200 km wide as seen from the spacecraft, 6,000 km away.

The Venus Express team deduced that from these observations, the cloud particles are estimated to be 1.2 micrometres across, roughly a fiftieth of the width of a human hair.

The fact that the glory is 1,200 km wide means that the particles at the cloud tops are uniform on this scale at least.

The variations of brightness of the rings of the observed glory is different than that expected from clouds of only sulphuric acid mixed with water, suggesting that other chemistry may be at play.

One idea is that the cause is the “UV-absorber,” an unknown atmospheric component responsible for mysterious dark markings seen in the cloud tops of Venus at ultraviolet wavelengths. More investigation is needed to draw a firm conclusion.

Scientists also think that it would be possible to see a rainbow — and perhaps even a glory — on Titan since the atmosphere on this moon of Saturn is likely filled with methane droplets.

Source: ESA

February 28, 2014April 8, 2018 by Nancy Atkinson

Astrophotographer’s Dream: Venus and Milky Way Galaxy Over Singapore

Rise of Venus and the Milky Way in Singapore on Feb. 28, 2014. Credit and copyright: Justin Ng.

“My dream to capture the beautiful Milky Way galaxy in Singapore has finally come true this morning after the monsoon season is over,” said noted astrophotographer Justin Ng, who lives in this island country in South East Asia. Justin noted that since Singapore is known for its heavy light pollution, there are many people who believe it’s impossible to capture stars and the arc of the Milky Way under those conditions. Justin has been taking amazing deep sky and night sky photos for quite some time, but he said with this particular image he’s hoping to prove the naysayers wrong.

“Plus, I hope to inspire more astrophotographers residing in heavily light polluted city to try to capture these ‘impossible’ images,” Justin added.

UPDATE: Below is a new timelapse video from Justin Ng.

This is a single exposure shot of planet Venus and Milky Way Galaxy in Singapore. However, the light pollution near the horizon is also visible.

Justin has now created a timelapse of his Milky Way photography from the same night he took this image, and he says a timelapse like this never been attempted by any photographers in Singapore, this is is the first:

Rise of Milky Way and Venus in Singapore from Justin Ng Photo on Vimeo.

You can see more of Justin’s fantastic astrophotography at his website, on G+, Facebook and Twitter.

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.

February 26, 2014December 23, 2015 by David Dickinson

Spectacular Views of Venus and the “Decrescent” Moon Worldwide

Did you see it? Earlier this week, we wrote about the spectacular conjunction of the planet Venus and the waning crescent Moon this week, which culminated in a fine occultation of the planet by our large natural satellite on Wednesday morning. The footprint of the occultation crossed northern Africa in the predawn hours to greet daytime observers across southern Asia. And although the pass was a near miss for many, viewers worldwide were treated to a fine photogenic pairing of Venus and the Moon.

Credit: SculptorLil — An “aircraft/Moon/Venus tri-conjunction” captured February 26th from London, UK. Credit: Sculptor Lil

This was a highlight event of the 2014 dawn apparition of Venus, and some great pics have been pouring in to us here at Universe Today via Twitter, Google+ and our Flickr pool. We also learned a new word this week while immersed in astronomical research: a decrescent Moon. We first thought this was a typo when we came across it, but discovered that it stands for a waning crescent Moon going from Last Quarter phase to New. Hey, it’s got a great ring to it, and its less characters than “waning crescent” and thus comes ready Tweet-able.

Venus and the Moon in the predawn sky captured from Israel. Credit: Gadi Eidelheit @gadieid

Some great video sequences have emerged as well, including this fine grazing sequence of a daytime crescent Venus brushing past the crescent Moon taken by Shahrin Ahmad:

Shahrin journeyed to the northern tip of Peninsular Malaysia to the town of Perlis near near the Thai border to capture the graze. “It was a really close event,” he noted. “Today, the clouds began to appear and posed some real tense moments during the occultation.”

And although many weren’t fortunate enough to be in the path of the occultation, many observers worldwide captured some very photogenic scenes of the conjunction between the Moon and Venus as the pair rose this morning, including this great video sequence from Ryan Durnall:

And clear skies greeted a series of early morning astronomers worldwide, who shared these amazing images with us:

This morning’s conjunction as imaged from Newark, New York. Credit- Brad Timerson @btimerson

Venus and the Moon the day prior to the occultation, shot by Ken Lord from Maple Ridge, British Columbia. Credit- Ken Lord.

The Moon approaching Venus on February 25th as seen from Carbon County, Pennsylvania. Credit: Tom Wildoner.

Venus and the Moon rising through the fog: Credit: Joanie Boloney @jstabila

John Chumack was also up early this morning and was able to capture this fine image of the pair rising above the University of Dayton’s PAC Center:

Venus and the Moon as seen from Dayton, Ohio. Credit: John Chumack, www.galacticimages.com

“All I had available was a point and shoot camera (not even mine!)” Chumack told Universe Today. “I’m surprised it came out okay, considering all the ambient light on Campus!!!” Chumack used a Fujifilm Finepix S1000 point and shoot camera, and went sans tripod, doing a 2″ exposure with the camera perched atop a trash can. The results of this ad hoc setup look great!

Astrophotographer Giuseppe Petricca based in Pisa, Italy north of the occultation path also grabbed this outstanding closeup image of the crescent pair:

Taken using a Nikon Coolpix P90 Bridge camera on a tripod mount. Credit: Giuseppe Petricca

“This morning was awesome!” Petricca told Universe Today. “The weather forecast showed a compact high layer of clouds, but there were enough gaps between them that allowed me to see the conjunction in a lot of different moments.”

You can compare and contrast the twin crescents of Venus and the Moon evident in the above image. “You can easily see the phase of the Planet Venus and a lot of details on the lunar surface, despite the high clouds that partially blocked the view sometimes!” Petricca noted.

And finally, I give you our own humble entry, a conjunction over suburbia snapped pre-caffeination:

We think its great that you can sometimes catch a memorable glimpse of the celestial even from your own doorstep.

And when is the next occultation of a planet by the Moon? That would be next month, when Saturn is occulted by the waxing gibbous Moon for South Africa and Brazil after sunset on March 21^st, 2014. We’re in the midst of a cycle of occultations of the ringed planet by the Moon, occurring every lunation through the final one this year on October 25th.

The next occultation of Venus occurs on October 23^rd 2014, but is only one degree from the Sun and is unobservable. The next observable event occurs on July 19^th 2015 for northern Australia in the daytime, and for a remote stretch of the South Pacific at dusk.

And its still not too late to spy Venus in the daytime today, using the nearby Moon as a guide. Here’s a handy simulation to aid you in your quest generated for mid-noon, February 26th:

And finally here’s handy chart of maps of occultations of Venus by the Moon for the current decade, just click to enlarge:

Occultations of Venus by the Moon from 2011-2020. Created using Occult 4.0.

Enjoy!

February 24, 2014April 26, 2016 by David Dickinson

Watch the Moon Meet Venus in the Dawn this Wednesday

The view of Wednesday's conjunction from selected sites based on four separate continents. Credit: Created by the author using Stellarium.

Are you ready for some lunar versus planetary occultation action? One of the best events for 2014 occurs early this Wednesday morning on February 26^th, when the waning crescent Moon — sometimes referred to as a decrescent Moon — meets up with a brilliant Venus in the dawn sky. This will be a showcase event for the ongoing 2014 dawn apparition of Venus that we wrote about recently.

This is one of 16 occultations of a planet by our Moon for 2014, which will hide every naked eye classical planet except Jupiter and only one of two involving Venus this year.

An occultation occurs when one celestial body passes in front of another, obscuring it from our line of sight. The term is used to refer to planets or asteroids blocking out distant stars or the Moon passing in front of stars or planets.

Wednesday’s event has a central conjunction time of 5:00 Universal. Viewers in northwestern Africa based in Mali and southern Algeria and surrounding nations will see the occultation occur in the dawn sky before sunrise, while viewers eastward across the Horn of Africa, the southern Arabian peninsula, India and southeast Asia will see the occultation occur in the daylight.

A comparison of Venus versus the Moon in the daytime taken by Sharin Ahmad (@shahgazer) from Malaysia during the last lunation on January 29th, 2014.

Observers worldwide, including those based in Australia, Europe and the Americas will see a near miss, but early risers will still be rewarded with a brilliant dawn pairing of the second and third brightest objects in the night sky. This will also be a fine time to attempt to spot Venus in the daytime, using the nearby crescent Moon as a guide. It’s easier than you might think! In fact, Venus is actually brighter than the Moon per apparent square arc second of surface area, owing to its higher average reflectivity (known as albedo) of 80% versus the Moon’s dusky 14%.

The International Occultation Timing Association also maintains a chart of ingress and egress times for specific locations along the track of the occultation.

Credit: Created using Occult 4.0.11. — The footprint of the Wednesday occultation of Venus by the Moon. Solid lines indicate where the occultation occurs before sunrise, while the dashed area denotes where the occultation occurs after sunrise. Credit: Created using Occult 4.1.0.11.

The Moon occults Venus 21 times in this decade. The last occultation of Venus by the Moon occurred on September 8^th, 2013, and the next occurs October 23rd 2014 over the South Pacific in daylight skies very close to the Sun, and is unobservable.

Wednesday’s event also offers a unique opportunity to catch a crescent Venus emerging from behind the dark limb of the Moon. On Wednesday, Venus presents a 34” diameter disk that is 35% illuminated and shining at magnitude -4.3, while the Moon is a 12% illuminated crescent three days from New. Fun fact: February 2014 is missing a New Moon, meaning that both January and March will each contain two!

Apparent path of Venus in relation to the Moon Wednesday morning as seen from a theoretical geocentric (Earth-centered) location. Created using Starry Night Education software.

This also means that a well positioned observer in northwestern Africa would be able to see able to catch the dark limb of Venus creeping out from behind the nighttime side of the Moon against a dark sky. Such favorable occurrences only happen a handful of times per decade, and this week would be a great time to try and briefly spot – or perhaps even video or photograph – a phenomenon know as the ashen light of Venus as the dazzling crescent daytime side of the planet lay obscured by the Moon. Is this effect reported by observers over the years a fanciful illusion, or a real occurrence?

Perhaps, due to the remote location, this chance to spy and record this elusive effect will go unnoticed this time ‘round. The next chance with optimal possibilities to catch a crescent Venus occulted by the Moon against a dark sky occurs next year on October 8th, 2015, favoring the Australian outback. Anyone out there down for an observing expedition to prove or disprove the ashen light of Venus once and for all? Astronomy road trip!

Photo by Author — April 22nd, 2009 conjunction of Venus and the Moon as seen from Hudson, Florida. The Photo by author.

This event also provides optimal circumstances as Venus heads towards greatest elongation west of the Sun on March 22^nd and the Moon-Venus pair lay 43 degrees west of the Sun during Wednesday’s event. Compare this to the impossible to observe occultation this October, when the pairing is only one degree east of the Sun! The next occultation of Venus for North America occurs next year on December 7th, 2015 and will be visible in the daytime across the extent of the track except for Alaska and Northwestern Canada.

Vexillographers may also want to take note: this week’s Venus-Moon pairing will closely emulate the familiar crescent Moon plus star pairing seen on many national flags worldwide. Did an ancient and unrecorded occultation of Venus by the Moon inspire this meme? Tradition has it that Sultan Alp Arslan settled on the star and crescent for the flag of the Turks after witnessing a close conjunction after the defeat of the Byzantine Army at the Battle of Manzikert on August 26^th, 1071 A.D. This tale, however, is almost certainly apocryphal, as no occultations of planets or bright stars by the Moon occurred on or near that date, and only two occultations of Venus by the Moon occurred that year. And Venus was less than two degrees from the Sun on that date, yet another strike against it. In fact, the only occultations of Venus by the Moon in 1071 occurred on June 29^th and November 27^th. Perhaps Arslan just took a while to decide…

Still, this week’s event provides a great photo-op to have “Fun with Flags” and capture the pair behind your favorite astronomical conjunction-depicting banner. And be sure to send those pics into Universe Today… methinks there’s a good chance of us running a post occultation photo-essay later this week!

February 5, 2014December 23, 2015 by Ken Kremer

Mariner 10: Best Venus Image and 1st Ever Planetary Gravity Assist – 40 Years Ago Today

On Feb. 5, 1974, NASA's Mariner 10 mission took this first close-up photo of Venus during 1st gravity assist flyby. Credit: NASA

Exactly 40 Years ago today on Feb. 5, 1974, Mariner 10, accomplished a history making and groundbreaking feat when the NASA science probe became the first spacecraft ever to test out and execute the technique known as a planetary gravity assisted flyby used to alter its speed and trajectory – in order to reach another celestial body.

Mariner 10 flew by Venus 40 years ago to enable the probe to gain enough speed and alter its flight path to eventually become humanity’s first spacecraft to reach the planet Mercury, closest to our Sun.

Indeed it was the first spacecraft to visit two planets.

During the flyby precisely four decades ago, Mariner 10 snapped its 1st close up view of Venus – see above.

From that moment forward, gravity assisted slingshot maneuvers became an extremely important technique used numerous times by NASA to carry out planetary exploration missions that would not otherwise have been possible.

For example, NASA’s twin Voyager 1 and 2 probes launched barely three years later in 1977 used the gravity speed boost to conduct their own historic flyby expeditions to our Solar Systems outer planets.

Mariner 10's Mercury. This is a photomosaic of images collected by Mariner 10 as it flew past Mercury on 29 March 1974. It shows the southern hemisphere. The spacecraft took more than 7,000 images of Mercury, Venus, the Earth, and the moon during its mission. Credit: NASA — Mariner 10’s Mercury.
This is a photomosaic of images collected by Mariner 10 as it flew past Mercury on 29 March 1974. It shows the southern hemisphere. The spacecraft took more than 7,000 images of Mercury, Venus, the Earth, and the moon during its mission. Credit: NASA

Without the flyby’s, the rocket launchers thrust by themselves did not provide sufficient interplanetary speed to reach their follow on targets.

NASA’s Juno Jupiter orbiter just flew back around Earth this past October 9, 2013 to gain the speed it requires to reach the Jovian system.

The Mariner 10 probe used an ultraviolet filter in its imaging system to bring out details in the Venusian clouds which are otherwise featureless to the human eye – as you’ll notice when viewing it through a telescope.

Venus surface is completely obscured by a thick layer of carbon dioxide clouds.

The hellish planet’s surface temperature is 460 degrees Celsius or 900 degrees Fahrenheit.

Diagram of Mariner 10 which flew by Venus and Mercury in 1974 and 1975. This photo identifies various parts of the spacecraft and the science instruments, which were used to study the atmospheric, surface, and physical characteristics of Venus and Mercury. This was the sixth in the series of Mariner spacecraft that explored the inner planets beginning in 1962. Credit: Jet Propulsion Laboratory

Following the completely successful Venus flyby, Mariner 10 eventually went on to conduct a trio of flyby’s of Mercury in 1974 and 1975.

It imaged nearly half of the planets moon-like surface, found surprising evidence of a magnetic field, discovered that a metallic core comprised nearly 80 percent of the planet’s mass, and measured temperatures ranging from 187°C on the dayside to minus 183°C on the nightside.

Mercury was not visited again for over three decades until NASA’s MESSENGER flew by and eventually orbited the planet – and where it remains active today.

Mariner 10 was launched on Nov. 3, 1973 from the Kennedy Space Center atop an Atlas-Centaur rocket.

Mosaic of the Earth from Mariner 10 after launch. Credit: NASA

Shortly after blastoff if also took photos of the Earth and the Moon.

Ultimately it was the last of NASA’s venerable Mariner planetary missions hailing from the dawn of the Space Age.

Mariner 11 and 12 were descoped due to congressional budget cuts and eventually renamed as Voyager 1 and 2.

The Mariner 10 science team was led by Bruce Murray of the Jet Propulsion Laboratory (JPL), Pasadena, Calif.

Murray eventually became the Director of JPL. After he passed away in 2013, key science features on Martian mountain climbing destinations were named in his honor by the Opportunity and Curiosity Mars rover science teams.

Stay tuned here for Ken’s continuing LADEE, Chang’e-3, Orion, Orbital Sciences, SpaceX, commercial space, Mars rover and more planetary and human spaceflight news.

Ken Kremer

Mariner 10 trajectory and timeline to Venus and Mercury. Credit: NASA

Diagram of the Mariner series of spacecraft and launch vehicle. Mariner spacecraft explored Mercury, Venus and Mars. Credit: Jet Propulsion Laboratory

Mosaic of Earth from Juno gravity assist Flyby in 2013 –
compare to Mariner 10 Earth mosaic above from 1973 to see advances in space technology
This false color composite shows more than half of Earth’s disk over the coast of Argentina and the South Atlantic Ocean as the Juno probe slingshotted by on Oct. 9, 2013 for a gravity assisted acceleration to Jupiter. The mosaic was assembled from raw images taken by the Junocam imager. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo

February 3, 2014December 23, 2015 by David Dickinson

Watch Venus as it Wanders Through the Dawn in 2014

Venus as captured by Shahrin Ahmad (@shahgazer) on January 31st, 2014. Credit- Shahgazer.net.

Are you a chronic early riser? Observational astronomy often means late nights and early mornings as daylight lengths get longer for northern hemisphere residents in February through March. But this year offers another delight for the early morning crowd, as the Venus is hanging out in the dawn skies for most of 2014.

You may have already caught sight of the brilliant world: it’s hard to miss, currently shinning at a dazzling -4.5 magnitude in the dawn. Venus is the brightest planet as seen from Earth and the third brightest natural object in the night sky after the Sun and the Moon.

Venus just passed between the Earth and the Sun last month on January 11th at inferior conjunction. Passing over five degrees north of the Sun, this was a far cry from the historic 2012 transit of the solar disk, a feat that won’t be replicated again until 2117 AD.

But February and March offer some notable events worth watching out for as Venus wanders in the dawn.

The path of Venus from February 4th to September 23rd, 2014. The first (top) graphic lays out the path as seen at dawn from latitude 30 degrees north, while the bottom lays out the path of Venus as seen from latitude 30 degrees south. Note that the orientation of the ecliptic in the top frame is set for September 23rd, while the bottom frame is set for February 4th, respectively. Created using Starry Night Education software.

This week sees Venus thicken as a 48” 16% illuminated waxing crescent as it continues to present more of its daytime side to the Earth. We’ve always thought that it was a bit of cosmic irony that the closest planet too us presents no surface detail to observers: Venus is a cosmic tease. This assured that astronomers knew almost nothing about Venus until the dawn of the Space Age — guesses at its rotational speed and surface conditions were all widely speculative. Ideas of a vast extraterrestrial jungle or surface-spanning seas of seltzer water oceans gave way to the reality of a shrouded hellish inferno with noontime temps approaching 460 degrees Celsius. Venus is also bizarre in the fact that it rotates once every 243 Earth days, which is longer than its 224.7 day year — you could easily out walk a Venusian sunrise, that is if you could somehow survive to see it from its perpetually clouded surface!

Venus also passes 4.3 degrees from faint Pluto this week on February 5^th. And while Pluto is a tough catch at over a million times fainter than Venus, it’s interesting to consider that NASA’s New Horizons and ESA’s Rosetta spacecraft are also currently off in the same general direction:

Venus and the invisible lineup of deep space missions in the same general direction this week. Also note that Venus has been skirting the non-zodiac constellation of Scutum this season! Created using Starry Night Education Software, — Venus and the invisible lineup of deep space missions in the same general direction this week. Also note that Venus has been skirting the non-zodiacal constellation of Scutum this season! Created using Starry Night Education Software.

Venus also reaches greatest brilliancy at magnitude -4.6 next week on February 11^th. Venus is bright enough to cast a shadow onto a high contrast background, such as freshly fallen snow. Can you see your “Venusian shadow” with the naked eye? How about photographically?

Venus then goes on to show its greatest illuminated extent to us on February 15^th. This combination occurs because although the crescent of Venus is fattening, the apparent size of the disk is shrinking as the planet pulls away from us in its speedy interior orbit. Can you spy the elusive “ashen light of Venus” through a telescope? Long a controversy, this has been reported by observers as a dim “glow” on the nighttime hemisphere of Venus. Proposed explanations for the ashen light of Venus over the years have been airglow, aurorae, lightning, Venusian land clearing activity (!) or, more likely, an optical illusion.

And speaking of which, the crescent Venus gets occulted by the waning crescent Moon on February 26^th. Observers in western Africa will see this occur in the predawn skies, and the rest of us will see a close pass of the pair worldwide. Can you spot Venus near the crescent Moon in the daytime sky on the 26^th?

The Moon and Venus at dawn on February 25th for observers along the U.S. Eastern Seaboard. Created using Stellarium.

In March, Venus begins the slide southward towards the point occupied by the Sun months earlier and heads towards its greatest westward elongation for 2014 on March 22^nd at 46.6 degrees west of the Sun. Interestingly, Venus is tracing out roughly the same track it took 8 years ago in 2006 and will trace again in 2022, when it will also spend a majority of the year in the dawn once again. The 8-year repeating cycle of Venus is a result of the planet completing very nearly 13 orbits of the Sun to our 8. Ancient cultures, including the Maya, Egyptians, and Babylonian astronomers all knew of this period.

Through the telescope, Venus appears at a tiny “half-moon” phase 50% illuminated at greatest elongation, a point known as dichotomy. It’s interesting to note that theoretical and observed dichotomy can actually vary by several days surrounding greatest elongation. An optical phenomenon, or a true observational occurrence? When do you judge that dichotomy occurs in 2014?

In April, one of the closest planetary conjunctions occurs of 2014 on the 12^th involving Neptune and Venus at just 40’ apart, a little over the span of a Full Moon. Can you squeeze both into an eyepiece field of view? At +7.7th magnitude, Neptune shines at over 25,000 times fainter than Venus. Neith, the spurious “moon” of Venus described by 18th century astronomers lives!

But two even more dramatic conjunctions occur late in the summer, when Jupiter passes just 15’ from Venus on August 18^th and Regulus stands just 42’ from Venus on September 5^th. Fun fact: Venus actually occulted Regulus last century on July 7th, 1959!

From there on out, Venus heads toward superior conjunction on the far side of the Sun on October 25th, to once again emerge into the dusk sky through late 2014 and 2015.

Be sure to check out these dawn exploits of Venus through this Spring season and beyond!

January 25, 2014December 23, 2015 by Bob King

Lovejoy and X1 LINEAR: How to See Comets That Will Warm Up Your Mid-Winter Mornings

Comet Lovejoy still shows both an ion tail (blue) and dust tail in this photo taken Jan. 12 from Stixendorf, Austria. Credit: Michael Jaeger

My hands are still cold from the experience, but there’s no denying the pleasure I felt at seeing C/2013 R1 Lovejoy and C/2012 X1 LINEAR through the telescope this morning. Some comets fizzle, others fall apart, but these vaporous hunks have hung in there for months like steadfast friends that stick with you through hard times and good.While no longer visible with the naked eye, 50mm binoculars easily show it as a magnitude 7 fuzzy glow with a short, faint tail pointing up and away to the northwest. I had no difficulty seeing it even with a last quarter moon glaring in the south.

Comets Lovejoy and X1 LINEAR are both moving across northern Ophiuchus. This map shows the sky facing east about 1 hour 45 minutes before sunrise shortly before the start of morning twilight. Detailed map below. Stellarium — Comets Lovejoy and X1 LINEAR are neighbors in northern Ophiuchus this month and next. This map shows the sky facing east about 1 hour 45 minutes before sunrise shortly before the start of morning twilight. Tick marks show the comets’ position every 5 days. Click to enlarge. Detailed map below. Created with Chris Marriott’s SkyMap software.

Rising around 3 a.m., Lovejoy is best placed for viewing just before the start of dawn when it climbs to about 30 degrees altitude in Ophiuchus. Lucky for us, Lovejoy will spend the next few mornings very close to the easy naked eye star 72 Ophiuchi, located 3 fists held at arm’s length to the lower right of brilliant Vega. It’s not often that a fairly bright comet passes this close to a helpful guide star. Don’t miss this easy catch. Soon the moon won’t be any trouble either as it skedaddles eastward and dwindles to a crescent in the coming mornings.

This deeper map shows stars to about magnitude 8. Although both comets appear to be getting lower every morning, the seasonal drift of the star to the west will keep them in good view for the next few months. Stellarium — This deeper map shows stars to about magnitude 8. Although both comets appear to be getting lower every morning, the westward seasonal drift of the stars will keep them in good view for the next few months. Click to enlarge. Created with Chris Marriott’s SkyMap software

Telescopic views of Lovejoy show a much diminished coma and tail compared to its heyday in early December. Still, the nucleus remains bright and very condensed within the 3′ diameter gauzy coma; a faint and silky tail 2/3 of a degree long flowed across the field of view of my 15-inch (37-cm) reflector like a bride’s train. According to the excellent Weekly Information about Bright Comets site maintained by Seiichi Yoshida, Lovejoy should glow brighter than magnitude 8, what I consider the “bright” comet cutoff, through early February. Given that Lovejoy remains the brightest predicted comet visible till summer, show it some love the next clear night.

Comet C/2012 X1 LINEAR shows a green coma from fluorescing gases and a short tail in this photo made on Jan. 15, 2014. Credit: Rolando Ligustri

If Lovejoy’s a fading celebrity, X1 LINEAR suffered a mid-life crisis and snapped out of it with a whole new attitude. Like Comet Holmes in 2007, it catapulted in brightness overnight in last October, blossoming from a 14th magnitude blip into a bright, expanding puffball briefly visible in ordinary binoculars. As expected, the comet soon faded. But on its return to obscurity, X1 surprised again, re-brightening and growing a short tail. Now it’s humming along at 9th magnitude thank you very much. You’ll find it gliding across northern Ophiuchus not far from Lovejoy (more about that in a minute).

Very different appearance of C/2012 X1 LINEAR during outburst on Oct. 21, 2013. Credit: Ernesto Guido, Martino Nicolini & Nick Howes

My binoculars won’t show the comet but a 6-inch telescope will do the trick. Overall weaker in appearance than Lovejoy, X1 LINEAR has a slightly larger, more diffuse coma, brighter core and a short, faint tail pointing to the northwest. The comet will remain a fine target for smaller scopes through early March when it’s predicted to glow between magnitude 8 and 9.

Comets Lovejoy and X1 LINEAR will be closest together on the morning of Feb. 6 CST. Notice that they'll be in the company of numerous deep sky objects. Looks like a morning's worth of observing to me! Created with Chris Marriott's SkyMap software — Comets Lovejoy and X1 LINEAR will be closest together on the morning of Feb. 6 CST. A plethora of deep sky objects near them will make for a complete morning’s worth of sky watching! Click to enlarge. Created with Chris Marriott’s SkyMap software

Looking at the maps, you’ll see that our two comets’ paths intersect. While they won’t overlap on the same morning, Lovejoy and X1 LINEAR will be in conjunction on Feb. 6 when they’ll be just 2 degrees apart. Get that camera ready! Guided telephoto and wide-field telescopes will be perfect for catching this unusual duet.

Before I sign off, don’t forget all the other good morning stuff: Mars hovers above Spica high in the south-southwestern sky, Saturn invites inspection in the southeast and Venus is back in view in the east-southeast 45 minutes before sunup. A delicate crescent moon shines near Venus on Jan. 28 and 29. Such riches.