Tag Archives: conjunction

How to get to Mars in 1 minute and 7 seconds

Posted on by
9

Mars photographed with the C2 coronagraph on SOHO (Solar and Heliospheric Observatory) earlier this morning. SOHO uses a disk to block the sun’s light so astronomers can study its atmosphere called the corona. Mars appears next to the sun only because it’s in the same line of sight. The planet’s actually in the distant background. Credit: NASA/ESA

On April 17 the Red Planet and Earth will line up on opposite sides of the sun, an event called solar conjunction. Other than not being able to see Mars because it’s hidden in the solar glare, the event has one real consequence for earthlings. We’ll explore that in a minute. Let’s just say that since the two planets now sit at opposite ends of the seesaw, Mars is about as far away as it gets, winking at Earth across a distance of 225.7 million miles. Compare that to 35 million when we’re closest.

That’s OUT THERE. Even light, traveling at 186,000 miles per second, takes 20 minutes to cross the gulf separating Earth from Mars. That means a 40 minute round trip for radio communications between the Curiosity and Opportunity rovers and mission control.

Screen grab from the “How Far is it to Mars?” site that give you a taste for how far the moon and Mars are from Earth. Click to go there. Credit: David Paliwoda and Jesse Williams

How would you like to get a feel for that distance? Understanding that time is precious, we’ll go easy on you by making the journey when Mars is closest to Earth. Normally it would take about 150 days to travel to the Red Planet using current technology. We’ll arrive quicker by accelerating to 3 times the speed of light. Even at that pace, you might be surprised how long it takes to arrive. Click HERE or on the image above to take the free journey. Bon voyage!

Curiosity drilled two holes in the “John Klein” rock in early February and gathered the powdered tailings to analyze its composition. The holes are each 2/3″ or 16mm across. On March 26, the rover used its powerful ChemCam laser to repeatedly zap the drilled powder, creating a row of tiny pits. The vaporized rock emitted light that was analyzed by Curiosity to determine its makeup. Click to enlarge. Credit: NASA/JPL-Caltech

Let’s return to the consequences of a Mars solar conjunction. As described in this earlier blog, Mars’ close alignment with the sun does affect our ability to communicate with the Opportunity and Curiosity rovers. Signals sent from Earth pass directly along the sun’s line of sight en route to Mars where they could be corrupted by solar radiation storms and electrified particles in the sun’s corona.

Interesting white rocks scattered about where Curiosity is stationed in Yellowknife Bay in Gale Crater. Notice how rounded some of the other pebbles are – possibly from water erosion. Click to enlarge. Credit: NASA/JPL-Caltech

It’s no big deal if bits of information go missing in a transmission from Curiosity, but if a bad command were sent from Earth, it might cause the robot to seize up or do damage to itself. To avoid potential problems, NASA has suspended communications for the remainder of April. Each day, Curiosity sends daily beeps to Earth telling mission control “I’m still here.”

Cool “aerial” view of Mt. Sharp inside Gale Crater (where Curiosity landed) taken by the orbiting Mars Odyssey satellite. The layering in the mountain at upper left may have been made when sediments were deposited by flowing waters. Click to enlarge. Credit: NASA/JPL/ASU

Mercury and Mars twist it up at dusk

Posted on by
11

Mars and Mercury have a quick tete-a-tete tonight Feb. 7 and Friday Feb. 8 low in the western sky in the direction of sunset. The scene shows the sky about 1/2 after sunset at which time Mercury will be about 8 degrees high. That’s just shy of one fist held at arm’s length against the sky. Created with Stellarium

It’s a long shot for some, but if you’ve got a wide open western horizon and clear sky tonight (Feb. 7) and tomorrow, you can watch a very close conjunction of Mercury and Mars. Mercury is just beginning its trek into the evening twilight, so it’s still low and soaked in solar glare. That will change next week when the planet climbs farther from the sun and becomes considerably easier to see.

Mars has been hanging around in twilight for months. Being on the faint side, it’s been a binoculars-only planet for many weeks. Mercury shines two magnitudes brighter at -1 and should just be visible with the naked eye in the darkening sky. Just the same, I’d bring binoculars if I were you. Scan a little ways above the west-southwest horizon about 30 minutes after sundown to locate Mercury. Once you see it, you’ll spot Mars about 3/4 degree (1.5 moon diameters) to its upper left tonight and 1/2 degree to its lower left Friday evening.

Good luck!

Jupiter and moon put on a great show at 18 below

Posted on by
8

The moon and Jupiter through a 400mm telephoto lens last night around 9:30 p.m. (CST) when they were near their closest separation. You can just make out Jupiter’s disk. Photo: Bob King

Jupiter and the moon were fabulous last night. I hope you got to see them. We were clear in Duluth, Minn. though there a price to be paid in frozen fingertips. The temperature hit -18 F at my house.

Our two celebs were so close together you could easily see the moon’s motion to the east in just 20 minutes. For a change, the air was tranquil overhead, giving steady, sharp images at the telescope. Craters like Copernicus, Plato and Tycho were crisply detailed and Europa’s shadow on Jupiter’s cloud tops looked like the most perfect of points.

Five of the 11-day-old moon’s most prominent craters are visible tonight in 8x (or higher) binoculars and small telescopes. Three of them – Copernicus, Kepler and Tycho – are surrounded by bright rays, which are aprons of impact debris. Plato has a smooth, dark, lava-flooded floor. Credit: Frank Barrett with my annotations

Tonight the moon moves further east into Taurus. As it waxes closer to full, we get more moon for our buck. That means more cool craters and alien terrain to pour over in binoculars and telescopes. I encourage you to take a look even if the weather bites. Just throw on a few more layers and laugh at the cold.

Heavy fog at -20 F over Lake Superior near the Lester River in Duluth, Minn. this morning. Cold air moving over the warmer lake condenses into tendrils of mist which gather into foggy clouds. Photo: Bob King

Beautiful Jupiter-moon conjunction on tap for tonight

Posted on by
2

A partial halo rings the moon and Jupiter (upper left) last night Jan. 20, 2013. Tonight the moon will sit right under the planet. Photo: Bob King

Ready for another one of Jupiter’s fly-by-night meetings with the moon? Tonight’s pairing of planet and moon will be the closest yet in a series that began last fall.

Observers in North and South America will get the best views at the most convenient hour. At 9 p.m. (CST) Jupiter will be just one moon diameter (1/2 degree) north of the moon and high in the southern sky.

The waxing gibbous moon and Jupiter will be closest around 9 p.m. (CST) together tonight Jan. 21, 2013 high above the constellation Orion. Maps created with Stellarium

Their proximity also means you have the opportunity to watch the moon “move its own diameter” in a hour. With Jupiter as a reference, you’ll easily see the two approach and separate during the evening. And yes, the moon moves a moon-span in about an hour as it orbits planet Earth. Check it out yourself.


Jupiter emerges in real time from behind the moon during the Dec. 25, 2012  occultation seen in Brazil. Credit: Carlos Bella

Sky watchers living across a wide swath of South America will get an extra treat – a Jupiter occultation. Because the moon is relatively close to Earth, its position shifts slightly against the background stars depending on your location. Seen from central S. America, it’s over 1/2 degree farther north compared to the view from northern U.S., putting it on a path to occult the planet. As the moon travels eastward during the night, it will first cover and then uncover Jupiter. Click HERE for a map and list of cities and times where the occultation will be visible.

Simulated view of the moon and Jupiter – with satellites Ganymede (G), Io (I) and Callisto (C) – as seen in binoculars and small telescopes tonight. North is up, west to the right.

Binoculars will show 2 or 3 Jovian satellites tonight depending on magnification and how steadily you can hold them. Through a telescope you’ll see all three plus be able to watch the shadow of Europa pass over the planet’s cloud tops between 9:18 p.m. and 12:52 a.m. (CST). Look for a tiny black pinprick south of Jupiter’s thick South Equatorial Belt (SEB).

A glance skyward tonight is all that’s necessary to witness this delightful celestial drama unfold. Don’t miss it. Skywatchers in the mainland U.S. won’t see Jupiter and the moon snuggled up this close again until Sept. 2, 2016!

Jupiter and the moon – what a show!

Posted on by
8

Jupiter and the moon 15 minutes before sunset. The photo captures their appearance in binoculars. Photo: Bob King

Did you catch the conjunction of Jupiter and the moon last night? Amazing sight. For fun I tried to see how early I could spot Jupiter once the moon rose high enough to clear the trees.

In 8×40 binoculars the planet was a pale, grey-white dot against a blue sky at 4:08 p.m. 15 minutes before sunset. With the nearby moon making it easy to know exactly where Jupiter was, spotting it was a snap.

The waxing gibbous moon and Jupiter light the way ahead in this picture taken during twilight last night Dec. 25, 2012. Photo: Bob King

How about naked eye? That took a few more minutes. At 4:15 p.m. it flashed weakly in and out of view as a faint pinprick. I could barely hold onto it, yet 15 minutes later in the post-sunset sky, Jupiter was unmistakeable.

By 11 p.m., when a halo circled the duo, the moon had moved off to the east of Jupiter. Photo: Bob King

The best views came as twilight deepened into night and the pair combined their lights for a stunning sight. Since the moon moves eastward as it revolves around the Earth, it creeps across the sky to the tune of 12 degrees (24 full moon diameters) each day. That’s one moon diameter per hour. Normally we don’t notice this movement during a single night, but last night was the exception. When the moon lines up with a bright object like a planet or star, its orbital motion is obvious.

The closest and arguable the best conjunction of Jupiter and the moon in the coming year happens on January 21, 2013. They two will be only a bit more than one moon diameter apart around 10 o’clock that evening. Created with Stellarium

Being so close to Jupiter, it was incredibly easy to see how its position changed with respect to the planet and also the nearby bright star Aldebaran. Even 20 minutes sufficed to see a noticeable change in position. When a beautiful halo surrounded the twosome at 11 p.m., the moon had already moved past Jupiter headed east. Cool!

If the weather didn’t cooperate for you last night, another Jupiter-moon conjunction will occur next month on January 21. At around 10 p.m. (CST) that night, they’ll be slightly closer than they were last night. After that, we’re pretty much done for the year. There’s a conjunction in March but it won’t be nearly as tight.

Tomorrow we’ll look back at 2012′s celestial highlights and then preview the coming year.

Mercury, Venus and Saturn align in the morning sky

Posted on by
6

Mercury, Venus and Saturn – along with Spica, which is similar to Saturn in brightness – will appear together in the southeastern sky at dawn. The maps show the scene about one hour before sunrise. Maps created with Stellarium

The upcoming Mercury-Venus-Saturn alignment, while not a real conjunction, is sure getting a lot of attention thanks to an inaccurate illustration on the Web depicting the three over the Pyramids of Giza. The planetary trio will be approximately equidistant and span an angle of 14 degrees (equal to 1 1/2 fists extended at arm’s length against the sky) on Monday morning Dec. 3. They’ll also appear in virtually the same lineup the mornings before and after.

When astronomers refer to a conjunction of two or more celestial bodies, they usually mean the objects are lined up closest together north-south of one another. When due south and highest in the sky, two planets in conjunction are stacked on top of each other. There are also conjunctions in longitude, when two celestial objects are closest together east-west or side-by-side.

Since none of the three planets is in conjunction, the Dec. 3 gathering is simply an interesting alignment. You’ll also notice from the diagram that for the next few mornings their configuration changes little. Tomorrow, Venus and Saturn will be a bit closer than Venus-Mercury; on Monday they’re equidistant and on Tuesday, Venus is closer to Mercury than Saturn.

The word planet comes from the Greek aster planetes or “wandering star”. And that’s exactly what they do. Ancient peoples thought they were carried around the Earth on invisible crystalline spheres. Today we know the truth – each orbits at a different distance from the sun with a period that depends on that distance. Mercury is closest and orbits fastest at 88 days; distant Neptune requires 165 years.

The ecliptic is the path followed by the planets, moon and sun across the sky. This narrow “highway” is a consequence of the planets orbiting the sun in nearly the same flat plane.

Planets are frequently in conjunction because they all follow the same path across the sky called the ecliptic.

It follows that if you’re all driving the same highway at different speeds, sooner or later two or more planets will pull up alongside each other. From our perspective, they’ll appear close together in the sky.

And since the planetary highway is approximately circular like a racetrack, interesting gatherings or conjunctions happen repeatedly over the months and years.

So if you combine the planets’ varying speeds according to distance, their shared “roadway” and our changing perspective on them as Earth revolves around the sun, you’ll understand why the current morning planet alignment will soon be broken.

Venus and the crescent moon about an hour before sunrise on Dec. 11.

No need to feel like you’re missing the opportunity of a lifetime though. Since these wandering stars are ever on the move, there’s an kaleidoscopic supply of conjunctions and alignments of every kind.

The really exciting ones usually involve the brightest planets or a planet-moon combo like the Jupiter-moon conjunction this past Wednesday.

Playing around with the free star-charting program Stellarium, I found that the next bright conjunction happens soon enough. On Dec. 11, the very thin crescent moon will be only 1.5 degrees south of Venus at dawn. It’s Christmas all year round when it comes to presents from the sky.

Need some dazzle in your life? Don’t miss tonight’s Jupiter-moon show

Posted on by
2

Jupiter (left), the moon and the Pleiades star cluster (upper right) last night Nov. 27, 2012. I partially hid the moon behind the tree during the exposure to better show the multicolored corona created by passing clouds. Click to learn more about coronas. Photo: Bob King

November’s been a wonderful month for conjunctions (close approaches) of the planets and moon. Tonight’s no exception. Jupiter and the Full Beaver Moon will be little more than one degree apart in the east all night long. I guarantee a lot of dazzle – this pairing is close enough to get the attention of anyone who happens to look up. Be sure to check it out.

The scene facing east around 10 o’clock local time. Jupiter and the full moon will be joined by the bright stars Capella, Betelgeuse and Aldebaran. Maps created with Stellarium

The two will be closest around 5:30 p.m. (CST). Since the moon is full and rises around sunset, you not only have a great opportunity to see how soon you can spot Jupiter after moonrise but also a chance to photograph the pair during twilight with an interesting foreground scene. For Duluth, Minn. the moon comes up at 4:38 p.m. To find the time for your town, just click HERE.

Simulated view of Jupiter and its four brightest moons seen through 10x binoculars or a small telescope tonight around 9 p.m. CST. II = Europa, I = Io, III = Ganymede and IV = Callisto.

If you stay up late, you’ll see the moon slowly slide under the planet as it heads east in its orbit around Earth. Have a scope or binoculars? Take a closer look at Jupiter – all four of its brightest moons will be lined up on either side of the planet.

You should be able to spot Europa and Callisto, the two farthest from the planet, with binoculars. A scope will show all four with ease. Enjoy the show!

Venus meets Saturn in a close conjunction tomorrow morning

Posted on by
6

Face southeast tomorrow and Tuesday mornings about an hour before sunrise to spot Venus paired up closely with the planet Saturn. Venus will appear like a brilliant star. Maps created with Stellarium.

Got your coat, hat and gloves? You’re ready then for tomorrow morning’s close conjunction of Venus and Saturn. The two will be just a half a degree or one full moon diameter apart in the southeastern sky at dawn. Look for fainter Saturn below Venus Monday; on Tuesday they’ll be equally close but switch positions. Though tight as two kernels on a cob, you’ll still be able to separate Venus from Saturn with your naked eye.

40-45 minutes before sunrise, Mercury will pop up in Libra to complete the line up of morning planets. Be sure you have a wide open view of  the southeastern sky to see it, since Mercury will only be about 5 degrees high at the time.

Telescope users have the pleasure of observing both planets in the same field of view. Venus presents a waxing gibbous disk, while Saturn’s rings are tilted open enough to be obvious even at 30x. Be sure to look for a little “star” floating immediately to the east of Saturn. That’s Titan, its brightest and largest moon.

Mercury has recently entered the morning sky as well, visible low in the southeast in morning twilight. Nothing like three planets for the price of one early rising.You may even get to see the space station by the Venus-Saturn. It happens at 6:18 a.m. on Nov. 27 for the Duluth, Minn. region. To check times and a map for your town, log on to Heavens Above.

The weather looks good here, so I plan to set the alarm for my first look at Saturn this season. I hope you’re able to do the same.

Moon drops in on Venus, Saturn before Tuesday’s solar eclipse

Posted on by
1

This map shows the sky facing southeast about an hour before sunrise. The lunar crescent stops near Venus Sunday morning the 11th and newly-emerging Saturn on Monday. Maps created with Stellarium

The moon’s on a tight schedule. So many places, so little time. It glides past Venus Sunday morning and a day later appears along a new morning planet, Saturn. Then on Tuesday – Weds. the new moon passes squarely in front of the sun for residents of northern Australia and several small islands in the Pacific for a solar eclipse appointment.

Venus and the moon at 9 a.m. local time with the sun well up in the southeastern sky.

Viewing the lunar crescent and Venus will be easy since both are bright and conveniently placed for viewing in morning twilight. For fun, see how long you can keep Venus in view after sunrise using the moon as a guide. If your sky is haze-free, I’m going to bet you’ll see it easily many minutes or even hours later. Let us know how you do.

The Saturn-moon conjunction Monday morning will be trickier, but worth the effort. Not only will you see the return of the ringed planet to the dawn sky but also a super-thin crescent. You’ll need a wide-open horizon to the east-southeast, since the pair will only be about 5 degrees high (about three fingers held together at arm’s length) an hour before sunrise. Bring binoculars as a back-up.

Anyone within the blue band will see a total solar eclipse Tuesday. Red marks the centerline of the eclipse. Cairns will get 2 minutes of totality. Maximum of 4 minutes happens over the South Pacific. Credit: NASA

On Nov. 14 about 6:30 a.m. Australian Eastern Standard time (4:30 p.m. CST Nov. 13) the moon will totally eclipse the sun during the early morning hours for lucky sky watchers in northern Australia.

The moon’s shadow first touches ground at sunrise in the wilds of the Northern Territory and tracks east at over a 1000 mph reaching the city of Cairns in Queensland with a population of about 150,000 at 6:39 a.m. local time.

Total solar eclipse south of Japan on July 22, 2009. The photographer caught the “diamond ring effect”, when the last bit of sunlight shines between mountains along the limb of the moon just before totality. Credit: AP Photo/Kyodo News, Akiko Matsushita

From there, totality races across the Coral Sea and South Pacific before wrapping up at sunset west of the Chilean coast. A much larger region including all of Australia, New Zealand, Papua New Guinea and southern South America will see varying degrees of partial eclipse.

From the northern hemisphere’s perspective, the moon misses the sun, passing to its south. Sorry, no eclipse. We’ll have to wait until August 21, 2017 for the next total solar eclipse. Click HERE for more details and times to watch Wednesday’s event down under.

Can’t afford a trip to Australia at the moment? Watch it instead via webcam. Here are some cams to check out when the time is nigh:

* University of North Dakota SEMS U-Stream
* Gorge Creek Orchards, Mareeba, North Australia
* Total solar eclipse carried by NASA
* Total solar eclipse from Oak Beech near Cairns, Queensland

Jupiter-moon main dish with a side salad of aurora tonight

Posted on by
11

Jupiter and the moon tonight

Don’t forget. Tonight Jupiter and moon are in conjunction and only about 2 degrees (four moon diameters) apart. Watch for the pair to rise in the northeastern sky around 8 p.m. local time.

While you’re out, turn your gaze to the northern sky. Recent solar CMEs (coronal mass ejections) have set the Earth’s magnetosphere aquiver, dumping high speed particles into the upper atmosphere to create auroras. The sky lit up over Norway last night from solar storms. Sky watchers in the northern U.S. may have their turn tonight. I’ll update the blog later today if auroras are imminent.

Moonlight reflects off waves on Lake Superior Monday night. Photo: Bob King

On Monday evening I got out in time to watch the full moon rise over Lake Superior. Moonrise occurred just 10 minutes before sunset, giving sky watchers that key 15-minute “photo window” when moonlight is balanced by the fading light of day. How pleasing to the eye to see a pink moon against Earth’s purplish shadow.

The full Hunter’s Moon rises over the lighthouse at the end of the Duluth, Minn. ship canal Monday night. Photo: Bob King