How to See Planet Neptune: Our Guide to Its 2013 Opposition

Neptune and its large moon Triton as seen by Voyager 2 on August 28th, 1989. (Credit: NASA).

If you do your own stargazing or participate in our Sunday night Virtual Star Parties, you’ve probably noticed we’re starting to lose planetary targets in the night-time sky. August and September of this year sees Venus and Saturn to the west at dusk, with the planets Mars and Jupiter adorning the eastern dawn sky just hours before sunrise.

That means there is now a good span of the night that none of the classic naked eye planets are above the horizon. But the good news is, with a little persistence, YOU can spy the outermost planet in our solar system in the coming weeks: the elusive Neptune. (Sorry, Pluto!)

A wide field view of Aquarius with Neptune's present position in late August/early September. (Created by the author i Stellarium).
A wide field view of Aquarius, with Neptune’s present position marked for late August/early September. (Created by the author in Stellarium; click on all star charts to enlarge).

The planet Neptune reaches opposition late this month in the constellation Aquarius on August 27th at 01:00 UT (9:00 PM EDT on the 26th). This means that it will rise to the east as the Sun sets to the west and will remain above the local horizon for the entire night.

If you’ve never caught sight of Neptune, these next few weeks are a great time to try. The Moon passes 6° north of the planet’s location this week on August 21st, just 10 hours after reaching Full.

neptune on the night of Opposition using a 4.4 degree field of view. (Created by the author using Stellarium).
Neptune on the night of Opposition using a 4.4 degree field of view. Magnitudes for nearby guide stars are given in red. (Created by the author using Stellarium).

Shining at magnitude +7.8, Neptune is an easy catch with binoculars from a dark sky site. Even in a large telescope, Neptune appears as a tiny blue dot, almost looking like a dim planetary nebula that refuses to come to a sharp focus. Visually, Neptune is only 2.3” across at opposition; you could stack 782 Neptunes across the breadth of the Full Moon!

It’s sobering to think that Neptune only just returned in 2011 to the position of its original discovery back in 1846. The calculation of Neptune’s position by Urbain Le Verrier was a triumph for Newtonian mechanics, a moment where the science of astronomy began to demonstrate its predictive power.

Astronomers knew of the existence of an unseen body due to the perturbations of the planet Uranus, which was discovered surreptitiously by William Herschel 65 years earlier. Using Le Verrier’s calculations, Johann Galle and Heinrich d’Arrest spied the planet on the night of September 23rd, 1846 using the Berlin observatory’s 9.6” refractor. Neptune was within a degree of the position described in Le Verrier’s prediction.

Neptune orbits the Sun once every 164.8 years, and comes back into opposition once every successive calendar year about 2 days later than the last. Those observers of yore were lucky that Neptune and Uranus experienced a close and undocumented conjunction in 1821; otherwise, Neptune may have gone undetected for a much longer span of time. And ironically, Galileo sketched the motion of Neptune near Jupiter in 1612 and 1613, but failed to identify it as a planet!

The motion of Neptune through Aquarius through late August into September. (Starry Night)
The motion of Neptune through Aquarius through late August into September. (Graphic created by author; courtesy of  Starry Night Education).

Neptune descended through the ecliptic in 2003 and won’t reach its southernmost point below it until 2045. This month, Neptune lies 1.5 degrees west of the +4.8 magnitude double star Sigma Aquarii. Neptune passes less than 4’ from +7.5 magnitude star HIP 110439 on September 9th as it continues towards eastern quadrature on November 24th.

Corkscrew chart credit:
Corkscrew chart for the elongations of Triton through early September. (Courtesy of Ed Kotapish; created using NASA/PDS Rings Node).

Up for a challenge? Neptune also has a large moon named Triton that is just within range of a moderate (8” in aperture or larger) telescope. Shining at magnitude +13.4, Triton is similar in brightness to Pluto and is 100 times fainter than Neptune. In fact, there’s some thought that Pluto may turn out to be similar to Triton in appearance when New Horizons gets a close-up look at it in July 2015.

Triton never strays more than 18” from Neptune during eastern or western elongations. This presents the best time to cross the moon off your astronomical “life list…” experienced amateurs have even managed to image Triton!

The moons of Neptune and Uranus imaged by Credit:
The moons of Neptune and Uranus imaged by Rolf Wahl Olsen using a 10″ reflector and a ToUCam Pro. An amazing catch! (Credit & Copyright: Rolf Wahl Olsen, used with permission).

Triton was discovered just 17 days after Neptune by William Lassell using a 24” reflector. Triton is also an oddball among large moons in the solar system in that it’s in a retrograde orbit.

A second moon named Nereid was discovered by Gerard Kuiper in 1949. To date, Neptune has 14 moons, including the recently discovered S/2004 N1 unearthed in Hubble archival data.

Neptune & Triton on the night of August 21st as it reaches greatest elongation. (Starry Night).
Neptune & Triton on the night of August 21st as it reaches greatest elongation. (Graphic created by author. Courtesy of Starry Night Education).

To date, Voyager 2 is the only spacecraft that has studied Neptune and its moons up close. Voyager 2 conducted a flyby of the planet in 1989. A future mission to Neptune would face the same dilemma as New Horizons: a speedy journey would still take nearly a decade to complete, which would rule out an orbital insertion around the planet. (Darn you, orbital mechanics!) In fact, New Horizons just crosses the orbit of Neptune at a distance of 30 astronomical units from the Earth in 2014.

Neptune is about four light hours away from the Earth, a distance that varies less than 20 minutes in light travel time from solar conjunction to opposition. And while Neptune and Triton may not appear like much more than dim dots through a telescope, what you’re seeing is an ice giant 3.8 times the diameter of the Earth, with a large moon 78% the size of our own.

Make sure to cross Neptune and Triton off of your bucket list… and next month, we’ll be able to do the same for the upcoming opposition of Uranus!

Poof! This Spacecraft Could Get Under A Planet’s Skin

A subsurface spacecraft prototype is deliberately slammed into 10 tonnes of ice in a rocket facility. Credit: European Space Agency/YouTube (screenshot)

If you want to get inside a planet or moon fast, the European Space Agency says lobbing a spacecraft at the surface might be a good approach.

This concept may sound like suicide. A recent prototype test, however, shows the spacecraft structure is mostly okay. Next step is figuring out what can survive on the inside.

ESA, like NASA and other agencies, isn’t afraid to test out new landing concepts if they suit better than the traditional ones (which use rockets and/or parachutes to land a spacecraft softly on the surface). Witness the Curiosity rover’s “seven minutes of terror” concept as a successful example.

Imagine that you want to look at water below the surface of Mars, or (like the people in Europa Report) you wish to plumb into the ice of Jupiter’s moon, Europa. One option could be a drill. Another one could be a subsurface spacecraft.

“One benefit over landers and rovers is that penetrators provide access to the subsurface without the need for additional drilling or digging,” ESA stated.

To test this out, engineers put 12 solid-propellant boosters on to a 44-pound (20 kilogram) prototype and fired it at almost the speed of sound at sea level: 1,118 feet a second (341 meters/second). (More technical details on the test).

The 1.5-second test, shown in the video, saw the prototype careening into 10 tonnes of ice at a deceleration of 24,000 times the force of gravity. Astronauts, by contrast, usually only withstand 3-4 g when going into space.

The scuffed and dented spacecraft was retrieved successfully, and now ESA is reviewing how well the internal structure held up in the chaos. They also plan to develop battery and communications systems that could somehow survive intact.

High-speed tests are not only useful for spacecraft landings, but also for meteor simulations.

Most meteors are comet dust striking at the atmosphere at speeds so high, they vaporiz in a blaze of light. This is a meteor from the Leonid shower in 2001. Credit: Bob King
Most meteors are comet dust striking at the atmosphere at speeds so high, they vaporiz in a blaze of light. This is a meteor from the Leonid shower in 2001. Credit: Bob King

An article in Wired recently covered the progress of the NASA Ames Vertical Gun range in its nearly 50 years of operation.

“Though it’s called a gun, the facility doesn’t look much like any firearm you’ve ever seen,” wrote Adam Mann. “The main chassis is a long metal barrel as thick as a cannon mounted on an enormous red pole that forks at the end into two legs.”

Check out how it’s studying meteor impacts on Mars in the Wired article.

Virtual Star Party – Aug. 18, 2013

On this warm August evening, three astronomers shared their live view of the night sky for a Virtual Star Party. The Moon was nearly full, but instead of hating it, Mark Behrendt decided to bring it into our view for the evening. We also had fantastic views of several of the famous summer nebulae: the Lagoon, the Swan, Veil, Ring, and Dumbbell Nebula.

Fraser also demonstrated his terrible skills as a space agency director, launching a few virtual rockets in the Kerbal Space Program while we waited for telescopes to update.

Host: Fraser Cain

Commentator: David Dickinson

Astronomers: Gary Gonella, Stuart Forman, Mark Behrendt

We run the Virtual Star Party as a live Google+ Hangout on Air every Sunday night when it gets dark on the West Coast. In the summer, that means 9:00 pm Pacific / 12:00 am Eastern. You can view the show live from the Universe Today YouTube page, or right here on Universe Today; we’ll embed the video on the site right before we begin.

We’re always looking for more astronomers, so if this sounds like something you’d like to participate it, just drop me an email at [email protected].

Astrophoto: The Milky Way Over Panther Creek State Park

The Milky Way arches over Jim Edgar Panther Creek State Park in Central Illinois. Credit and copyright: Ben Romang.

Amateur astronomers from Illinois frequently venture out to Jim Edgar Panther Creek State Park, a 26-square mile conservation area of prairie and forest, famous for having the darkest skies in the state. But of course, lots of folks head out to the park to enjoy other things like the picturesque landscapes, the wildlife, and the solitude.

This past week my friend Ben Romang went to do some camping at Panther Creek, and with a borrowed camera, wanted to make his first attempt at photographing the night sky. He was hoping to nab some Perseid meteors, but instead was overwhelmed with the beauty of the expansive sky overhead. For his first try, I think he did a pretty good job of capturing the view, don’t you?

Ben used a Canon 7D, with an EF 24-70mm lens.

If you’d like to see these amazing dark skies for yourself, the perfect time would be during the annual Illinois Dark Sky Star Party, held every year by the local astronomy group in my area, the Sangamon Astronomical Society. It’s a great event, with a wonderful observing site, lots of room for camping, great food, interesting speakers (so claims their website — I’ve spoken there a few times!), and very friendly folks who are passionate about amateur astronomy. This year the Dark Skies Party is October 3-6, 2013. Find out more about the event here.

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.

Update on the Bright Nova Delphini 2013; Plus a Gallery of Images from our Readers

The bright new Nova Delphini 2013, as seen from Puerto Rico on August 16th, 03:13ut Credit: Efrain Morales/Jaicoa Observatory.

Since showing itself on August 14, 2013, a bright nova in the constellation Delphinus — now officially named Nova Delphini 2013 — has brightened even more. As of this writing, the nova is at magnitude 4.4 to 4.5, meaning that for the first time in years, there is a nova visible to the naked eye — if you have a dark enough sky. Even better, use binoculars or a telescope to see this “new star” in the sky.

The nova was discovered by Japanese amateur astronomer Koichi Itagak. When first spotted, it was at about magnitude 6, but has since brightened. Here’s the light curve of the nova from the AAVSO (American Association of Variable Star Observers) and they’ve also provided a binocular sequence chart, too.

How and where to see the new nova? Below is a great graphic showing exactly where to look in the sky. Additionally, we’ve got some great shots from Universe Today readers around the world who have managed to capture stunning shots of Nova Delpini 2013. You can see more graphics and more about the discovery of the nova on our original ‘breaking news’ article by Bob King.

The new nova is located in Delphinus alongside the familiar Summer Triangle outlined by Deneb, Vega and Altair. This map shows the sky looking high in the south for mid-northern latitudes around 10 p.m. local time in mid-August. The new object is ideally placed for viewing. Stellarium
The new nova is located in Delphinus alongside the familiar Summer Triangle outlined by Deneb, Vega and Altair. This map shows the sky looking high in the south for mid-northern latitudes around 10 p.m. local time in mid-August. The new object is ideally placed for viewing. Stellarium

If you aren’t able to see the nova for yourself, there are a few online observing options:

The Virtual Star Party team, led by UT’s publisher Fraser Cain, will try to get a view during the next VSP, at Sunday night on Google+ — usually at this time of year, about 10 pm EDT/0200 UTC on Monday mornings. If you’d like a notification for when it’s happening, make sure you subscribe to the Universe Today channel on YouTube.

The Virtual Telescope Project, based in Italy, will have an online observing session on August 19, 2013 at 20:00 UTC, and you can join astronomer Gianluca Masi at this link.

The Slooh online telescope had an observing session yesterday (which you can see here), and we’ll post an update if they plan any additional viewing sessions.

There’s no way to predict if the nova will remain bright for a few days more, and unfortunately the Moon is getting brighter and bigger in the sky (it will be full on August 20), so take the opportunity this weekend if you can to try and see the new nova.

Now, enjoy more images from Universe Today readers:

Nova Delphini 2013 from August 16, 2013 at 0846 UTC. Credit and copyright: Nick Rose.
Nova Delphini 2013 from August 16, 2013 at 0846 UTC. Credit and copyright: Nick Rose.
The bright nova in Delphinus when it was at magnitude 6.1 on August 14, 2013, as see from Yellow Springs, Ohio USA. Credit and copyright: John Chumack/Galactic Images.
The bright nova in Delphinus when it was at magnitude 6.1 on August 14, 2013, as see from Yellow Springs, Ohio USA. Credit and copyright: John Chumack/Galactic Images.
Proving that Nova Delphini 2013 is now a bright, naked-eye object, this fun image shows not only the nova, but the surrounding landscape in Sweden of the photographer, too. Credit and copyright: Göran Strand.
Proving that Nova Delphini 2013 is now a bright, naked-eye object, this fun image shows not only the nova, but the surrounding landscape in Sweden of the photographer, too. Credit and copyright: Göran Strand.
Nova Delphinii 2013 as seen on August 15, 2013. Credit and copyright: Andre van der Hoeven
Nova Delphinii 2013 as seen on August 15, 2013. Credit and copyright: Andre van der Hoeven
Nova in Delphinus from Ottawa, Canada on August 14, 2013. 13 second exposure under heavy light pollution with Nikon D80. Credit and copyright: Andrew Symes
Nova in Delphinus from Ottawa, Canada on August 14, 2013. 13 second exposure under heavy light pollution with Nikon D80. Credit and copyright: Andrew Symes
Image of Nova Delphini 2013, on 15 Aug. 2013, via the Virtual Telescope Project/Gianluca Masi.
Image of Nova Delphini 2013, on 15 Aug. 2013, via the Virtual Telescope Project/Gianluca Masi.
Annotated image of Nova Delphini 2013, as seen from Hawaii. Credit and copyright: Bryanstew on Flickr.
Annotated image of Nova Delphini 2013, as seen from Hawaii. Credit and copyright: Bryanstew on Flickr.

Ralf Vandebergh shared this video he was able to capture on his 10-year-old hand-held video camera to “demonstration of the brightness of the nova and what is possible with even 10 year old technique from hand.”

Venus And Moon Caught In A Crazy, Phase-y Coincidence Tonight

Venus reflected in Boulder Lake north of Duluth, Minn. two nights ago. Credit: Bob King

Curious coincidences occur in the sky just as they do on Earth. Take tonight for instance. The moon is in gibbous phase or about 3/4 full – 78% to be exact – while Venus, which also undergoes phases identical to the moon, is likewise gibbous and 78% full.

That’s just cool. If you have telescope, focus on Venus low in the western sky just after sunset and see a perfect replica in miniature of tonight’s moon.

Look for the cloudy but beautiful planet about a fist up in the west-southwest shortly after sunset. Stellarium
Look for Venus about a fist up in the west-southwest shortly after sunset. Stellarium

Be sure you’re out early as the planet is low to begin with and drops lower in the west with each passing minute. Provided the sky is haze-free, Venus isn’t difficult to spot even 5 minutes after sunset. Look about 10 degrees (one fist held at arm’s length) above the west-southwest horizon.

The moon and Venus are coincidentally in exactly the same phase tonight - 78% gibbous. Stellarium
The moon and Venus are coincidentally in exactly the same phase tonight – 78% gibbous. Stellarium

The moon shows spectacular craters and mountains, but Venus hides its equally spectacular scenery of volcanic mountains, craters and cracked plains beneath a permanent cover of sulfur-dioxide-laced clouds. Clouds are excellent reflectors of sunlight. Not only is the planet brilliant because of them but looks as white as a shiny cue ball.

Venus' changing position with relation to the Earth as it orbits around the sun causes it to exhibit phases like the moon. I've marked approximately where Venus is in mid-August. After gibbous, the planet will wane to half and then a crescent over the coming months as it catches up and passes the Earth. Illustration: Bob King
Venus’ changing position with relation to the Earth as it orbits around the sun causes it to exhibit phases like the moon. I’ve marked approximately where Venus is in mid-August. After gibbous, the planet will wane to half and then a crescent over the coming months as it catches up and passes the Earth. Illustration: Bob King

Tomorrow night the moon and Venus will go their own phase-y way, the moon fattening up toward full and Venus slowly slimming its waistline as it works its way toward the Earth. For now enjoy their temporary bond.

Weekly Space Hangout – Aug. 16, 2013

Like your space news, but you just can’t handle reading any more? Then watch our Weekly Space Hangout, where we give you a rundown of all the big space news stories that broke this week.

Host: Fraser Cain

Panel: Brian Koberlein, David Dickinson, Nancy Atkinson, Nicole Gugliucci

Stories:
CIA Comes Clean About Area 51
Elon Musk’s Hyperloop
Space Fence Shut Down
Magnetar Discovered Near the Galactic Core
IAU Updates Their Naming Policy
Bright Nova in Delphinus

We record the Weekly Space Hangout every Friday at 12 pm Pacific / 3 pm Eastern as a live Google+ Hangout on Air. Join us live on YouTube, or you can listen to the audio after the fact on the 365 Days of Astronomy Podcast.

CIA’s Declassified Documents Reveals Secrets About Area 51 and UFOs

Area 51 shows up in Google Earth. Via Google Maps.

The CIA has released a 355-page document which officially acknowledges that Area 51 in Nevada does exist, and the agency comes clean about their weather balloon cover stories. The document covers the U-2 and SR-71 spyplane programs and Project OXCART, the aerial reconnaissance programs, from 1954 to 1974.

Nope, no revelations about extraterrestrial spacecraft or alien bodies hidden at the base, but a really grainy map showing the location of Area 51 is included.

While Area 51 has been the subject of fascination for conspiracy theorists and paranormal enthusiasts — and is entrenched in UFO-ology and pop culture — the newly declassified information (with surprisingly few redactions) admits the base was a top-secret aircraft testing facility for Cold War reconnaissance of the Soviet Union.

That UFO sightings increased during the times of the flight tests was an unexpected side effect, the document says:

High-altitude testing of the U-2 soon led to an unexpected side effect-a tremendous increase in reports of unidentified flying objects (UFOs). In the mid-1950s, most commercial airliners flew at altitudes between 10,000 and 20,000 feet and military aircraft like the B-47s and B-57s operated at altitudes below 40,000 feet. Consequently once U-2s started flying at altitudes above 60,000 feet, air-traffic controllers began receiving increasing numbers of UFO reports.

The document also explains Project Blue Book and other frequently associated UFO story staples. The job of Project Blue Book was actually to figure out when civilians were reporting UFOs that were actually U-2s and then work out how to keep that from happening again.

Why did people on the ground and even other pilots report “shiny” UFOs? The document explains that the U-2s silver wings were at the right altitude that when the ground below, or even planes flying at a lower altitude were in darkness, the U-2 was in sunlight and its silver wings would glint in the sunlight:

Such reports were most prevalent in the early evening hours from pilots of airliners flying from east to west. When the sun dropped below the horizon of an airliner flying at 20,000 feet. the plane was in darkness. But, if a U-2 was airborne in the vicinity of the airliner at the same its horizon from an altitude of 60,000 feet was considerably more distant, and being so high in the sky, its silver wings would catch and reflect the ray of the sun and appear to the airliner pilot 40,000 feet below to be fiery objects. Even during the daylight hours, the silver bodies of the high-flying U-2s could catch the sun and cause reflections or glints that could be seen at lower altitudes and even on the ground. At this time, no one believed manned flight was possible above 60,000 feet, so no one expected to see an object so high in the sky.

A handwritten document about the U-2 spyplane design that was included in the information released by the CIA about test flights and Area 51.
A handwritten document about the U-2 spyplane design that was included in the information released by the CIA about test flights and Area 51.

But then, not all the UFO reports were explained by U-2 flights.

Air Force investigators then attempted to explain such sightings by linking them to natural phenomena. BLUE BOOK investigators regularly called on the Agency’s Project Staff in Washington to check reported UFO sightings against U-2 flight logs. This enabled the investigators to eliminate the majority of the UFO reports, although they could not reveal to the letter writers the true cause of the UFO sightings. U-2 and later OXCART flights accounted for more than one-half of all UFO reports during the late 1950s and most of the 1960s.

In the document, the CIA admits the weather balloon stuff was just a cover story, but it was the standard operating procedure for how to explain away the sightings as well as debris from any crashes. However, this cover story ended up having disastrous results in May of 1960 when the crash of a U-2 in Russia and the subsequent capture of pilot Gary Powers set in motion a pattern of mistrust between the US and USSR that culminated in the Cuban Missile Crisis in 1962.

After the plane and the pilot went missing, and with the fate of the plane and pilot unknown, the CIA had NASA release a statement that they had a weather airplane that went off course over the Soviet Union because the pilot had passed out due to a loss of oxygen. That story was quickly proven to be a hoax when the USSR produced the crashed U-2 plane and the pilot, who survived the crash and who had admitted to spying.

The documents were released in response to a Freedom of Information Act request submitted in 2005 by Jeffrey T. Richelson, a senior fellow at the National Security Archives. Originally, the CIA had released a heavily redacted document with all mention of Area 51 blacked out. This new document reveals pretty much everything except names of military personnel and private citizens involved.

Richelson has pointed out that the location of Area 51 was not a particularly well-kept secret. Its location appears in satellite imagery like Google Maps and Google Earth, as well as in books on aerial surveillance.


You can wade through the 355 page document here.
If you enjoy military and aircraft history, its a great read. One interesting fact revealed is that President Eisenhower wanted the pilots of these planes to be non-US citizens. “It was his belief that, should a U-2 come down in hostile territory, it would be much easier for the United States to deny any responsibility for the activity if the pilot was not an American,” the document reports.

And while I have this chance, I’m going to share a great graphic going around Twitter on how to identify any strange light in the sky you may see:
light in the sky

Why the North Pole Is Really a South Pole (and Vice Versa)

If you go out hiking this weekend and somehow find yourself hopelessly lost in the wilderness, but suddenly remember you have a compass with you, you can use it to find north because the needle always points towards the Earth’s geographic north pole, which never changes… right?

Wrong, wrong, and wrong. And this video from MinutePhysics explains why.

(But still bring a compass with you. They do come in handy.)

See more videos from MinutePhysics here.

Dream Chaser Prepares For Flight After Crucial Ground Tests

Sierra Nevada Corp.'s Dream Chaser just before tow tests at NASA's Dryden Flight Research Center on Aug. 2, 2013. Credit: NASA/Ken Ulbrich

Another kind of commercial spacecraft is almost ready to take flight, its backers say.

Sierra Nevada Corp.’s Dream Chaser recently finished four low- and high-speed ground tests at NASA’s Dryden Flight Research Center in Edwards, Calif., the same spot where the shuttle was put through its paces in early tests of its program. Several shuttle flights also landed at Dryden.

The Dream Chaser tow-and-release tests, which took place at speeds ranging from 10 to 60 miles per hour (16 to 96 kilometers per hour), examined items such as the flight computer, how the guidance performed, steering parameters and the flight surfaces.

“Watching Dream Chaser undergo tow testing on the same runway where we landed several space shuttle orbiters brings a great amount of pride to our Dream Chaser team,” stated Steve Lindsey, SNC’s Space Systems senior director of programs, who is also a former NASA astronaut.

“We are another step closer to restoring America’s capability to return U.S. astronauts to the International Space Station.”

The next step will be an approach and landing test, which should take place sometime in the third quarter of 2013.

SNC is one of three companies receiving money from NASA under the agency’s commercial crew program, whose goal is to move astronaut launches back to American soil in the next few years. The other competitors are SpaceX and Boeing. You can read a more in-depth look at their proposals here.

Source: Sierra Nevada Corp.