We’re in the middle of Summer here on Vancouver Island, the Sun is out, the air is warm, and the river is great for swimming.
Three months from now, it’s going to be raining and miserable.
Six months from now, it’s still going to be raining, and maybe even snowing.
No matter where you live on Earth, you experience seasons, as we pass from Spring to Summer to Fall to Winter, and then back to Spring again.
Why do we have variations in temperature at all? What causes the seasons?
If you ask people this question, they’ll often answer that it’s because the Earth is closer to the Sun in the summer, and further in the winter.
But this isn’t why we have seasons. In fact, during Winter in the Northern Hemisphere, the Earth is actually at the closest point to the Sun in its orbit, and then farthest during the Summer. It’s the opposite situation for the Southern hemisphere, and explains why their seasons are more severe.
So if it’s not the distance from the Sun, why do we experience seasons?
We have seasons because the Earth’s axis is tilted.
Consider any globe you’ve ever used, and you’ll see that instead of being straight up and down, the Earth is at a tilt of 23.5-degrees.
The Earth’s North Pole is actually pointed towards Polaris, the North Star, and the south pole towards the constellation of Octans. At any point during its orbit, the Earth is always pointed the same direction.
For six months of the year, the Northern hemisphere is tilted towards the Sun, while the Southern hemisphere is tilted away. For the next six months, the situation is reversed.
Whichever hemisphere is tilted towards the Sun experiences more energy, and warms up, while the hemisphere tilted away receives less energy and cools down.
Consider the amount of solar radiation falling on part of the Earth.
When the Sun is directly overhead, each square meter of Earth receives about 1000 watts of energy.
But when the Sun is at a severe angle, like from the Arctic circle, that same 1000 watts of energy is spread out over a much larger area.
This tilt also explains why the days are longer in the Summer, and then shorter in the Winter.
The longest day of Summer, when the Northern Hemisphere is tilted towards the Sun is known as the Summer Solstice.
And then when it’s tilted away from the Sun, that’s the Winter Solstice.
When both hemispheres receive equal amounts of energy, it’s called the Equinox. We have a Spring Equinox, and then an Autumn Equinox, when our days and night are equal in length.
So how does distance from the Sun affect us?
The distance between the Earth and has an effect on the intensity of the seasons.
The Southern Hemisphere’s Summer happens when the Earth is closest to the Sun, and their winter when the Earth is furthest. This makes their seasons even more severe.
You might be interested to know that the orientation of the Earth axis is actually changing.
Over the course of a 26,000 year cycle, the Earth’s axis traces out a great circle in the sky. This is known as the precession of the equinoxes.
At the halfway point, 13,000 years, the seasons are reversed for the two hemispheres, and then they return to original starting point 13,000 years later.
You might not notice it, but the time of the Summer Solstice comes earlier by about 20 minutes every year; a full day every 70 years or so.
I hope this helps you understand why the Earth – and any planet with a tilted axis – experiences seasons.
Comet ISON, as seen on September 22, 2013 at 10:00 UTC (6:00 am EDT) from Yellow Springs, Ohio, using a QHY8 CCD camera and a home-made 16 inch diameter telescope. 15 minute exposure. Credit and copyright: John Chumack.
Perhaps you’ve read the news. This Fall, the big ticket show is the approach of Comet C/2012 S1 ISON. The passage of this comet into the inner solar system has been the most anticipated apparition of a comet since Hale-Bopp in 1997.
Many backyard observers will get their first good look at Comet ISON in the coming month. If you want to see this comet for yourself, here’s everything you’ll need to know!
A composite image of Comet ISON as seen from the Hubble Space Telescope on April 30th, 2013. (Credit: HubbleSite.org/Go/ISON).
Discovered on September 21st, 2012 by Artyom-Kislovodsk and Vitaly Nevsky using the International Scientific Optical Network’s (ISON) 0.4 metre reflector, this comet has just passed out from behind the Sun from our Earthly vantage point this summer to once again become visible in the dawn sky.
Of course, there’s much speculation as to whether this will be the “comet of the century” shining as “bright as the Full Moon” near perihelion. We caught up with veteran comet observer John Bortle earlier this year to see what skywatchers might expect from this comet in late 2013. We’ve also chronicled the online wackiness of comets past and present as ISON makes its way into the pantheon as the most recently fashionable scapegoat for “the end of the world of the week…”
But now it’s time to look at the astronomical prospects for observing Comet ISON, and what you can expect leading up to perihelion on November 28th.
Comet ISON as recently imaged by Efrain Morales on September 22nd. (Credit: Efrain Morales/Jaicoa Observatory, used with permission).
Advanced amateur astronomers are already getting good images of Comet ISON, which currently shines at around +12th magnitude in the constellation Cancer. And although NASA’s Deep Impact/EPOXI mission is down for the count, plans are afoot for the Curiosity rover and the Mars Reconnaissance Orbiter to attempt imaging the comet when it makes its closest approach to the Red Planet on October 1st at 0.0724 Astronomical Units (A.U.) or 10,830,000 kilometres distant. If MSL is successful, it would be the first time that a comet has been observed from the surface of another world.
Currently, ISON sits about a magnitude below the projected light curve, (see below) but that isn’t all that unusual for a comet. Already, there’s been increasing talk of “ISON being a dud,” but as Universe Today’s Nancy Atkinson pointed out in a recent post, these assertions are still premature. The big question is what ISON will do leading up to perihelion, and if it will survive its passage 1.1 million kilometres above the surface of the Sun on November 28th to become a fine comet in the dawn skies in the weeks leading up to Christmas.
ISON is already starting to show a short, spikey tail in amateur images. Tsutomu Seki estimated it to be shining at about magnitude +11.1 on September 16th. Keep in mind, a caveat is in order when talking about the magnitudes of comets. Unlike stars, which are essentially a point source, the brightness of a comet is spread out over a large surface area. Thus, a comet may appear visually fainter than the quoted magnitude, much like a diffuse nebula. Although +6th magnitude is usually the limit for naked eye visibility, I’ll bet that most folks won’t pick up ISON with the unaided eye from typical suburban sites until it breaks +4th magnitude or so.
The recent revised light curve projected for Comet ISON (Credit: NASA CIOC/Compiled by Matthew Knight of the Lowell Observatory).
The forward scattering of light also plays a key role in the predicted brightness of a comet. The November issue of Astronomy Magazine has a great article on this phenomenon. It’s interesting to note that ISON stacks up as a “9” on their accumulated point scale, right at the lower threshold of comet “greatness,” versus a 15 for sungrazing Comet C/1965 S1 Ikeya-Seki. Another famous “9” was Comet C/1996 B2 Hyakutake, which passed 0.1018 A.U. or 15.8 million kilometres from Earth on March 25, 1996.
ISON will pass 0.429 A.U. or 64.2 million kilometres from Earth the day after Christmas. Bruce Willis can stay home for this one.
Here is a blow-by-blow breakdown of some key dates to watch for as ISON makes its plunge into the inner solar system:
-September 25th: ISON crosses the border from the astronomical constellation of Cancer into Leo.
-September 27th: ISON passes 2 degrees north of the planet Mars.
The path of Comet ISON from October 1st to November 21st. The position of the Sun is shown on the final date. (Created by the Author using Starry Night Education software).
-October 1st: The 12% illuminated waning crescent Moon passes 10 degrees south of Mars & ISON.
-Early October: ISON may break +10th magnitude and become visible with binoculars or a small telescope.
-October 4th: New Moon occurs. The Moon then exits the dawn sky, making for two weeks of prime viewing.
–October 10th: ISON enters view of NASA’s STEREO/SECCHI HI-2A CAMERA:
-October 16th: ISON passes just 2 degrees NNE of the bright star Regulus, making a great “guidepost” to pin it down with binoculars.
-October 18th: The Full Moon occurs, after which the Moon enters the morning sky.
-October 26th: A great photo-op for astro-imagers occurs, as ISON passes within three degrees the Leo galaxy trio of M95, M96, & M105.
The position of Comet ISON on October 26th in Leo near Mars and a trio of galaxies. (Created by the author in Stellarium).
-October 30th: The 17% illuminated Moon passes 6 degrees south of ISON.
-Early November: Comet ISON may make its naked eye debut for observers based at dark sky sites.
-November 3rd: A hybrid (annular-total) solar eclipse occurs, spanning the Atlantic and Central Africa. It may just be possible for well placed observers to catch sight of ISON in the daytime during totality, depending on how quickly it brightens up. The Moon reaching New phase also means that the next two weeks will be prime view time for ISON at dawn.
-November 5th: ISON crosses the border from the astronomical constellation of Leo into Virgo.
-November 7th: ISON passes less than a degree from the +3.6 magnitude star Zavijava (Beta Virginis).
-November 8th: ISON passes through the equinoctial point in Virgo around 16:00 EDT/20:00 UT, passing into the southern celestial hemisphere and south of the ecliptic.
-November 14th: ISON passes less than a degree from the 10th magnitude galaxy NGC 4697.
-November 17th: The Moon reaches Full, passing into the morning sky.
-November 18th: ISON passes just 0.38 degrees north of the bright star Spica.
-November 22nd: ISON crosses into the astronomical constellation of Libra.
-November 23rd: ISON sits 4.7 degrees SSW of the planet Mercury and 4.9 SSW of Saturn, respectively.
Looking east before dawn on the morning of November 23rd. Note comet 2P/Encke nearby! (Created by the author using Starry Night Education software).
-November 25th: ISON pays a visit to another famous comet, passing just 1.2 degrees south of short period comet 2P/Encke which may shine at +8th magnitude.
-November 27th: ISON enters the field of view of SOHO’s LASCO C3 coronagraph.
-November 28th: ISON reaches perihelion at ~18:00 PM EST/ 23:00 UT.
After that, all bets are off. The days leading up to perihelion will be tense ones, as ISON then rounds the Sun on a date with astronomical destiny. Will it join the ranks of the great comets of the past? Will it stay intact, or shatter in a spectacular fashion? Watch this space for ISON updates… we’ll be back in late November with our post-perihelion guide!
Chinese taikonauts (from left) Liu Yang, Jing Haipeng and Liu Wang. Credit: www.news.cn
China’s human spaceflight program may soon be opening the door to foreign astronauts. The Asian nation has so far been forging ahead with a small space station and its own flights, independent of the multinational collaboration taking place with the International Space Station, although it has done work with Russia and France.
Last week, however, a Chinese official said the country is considering bringing foreign astronauts on board its spacecraft and also providing training for them.
“We would like to train astronauts from other countries and organizations that have such a demand, and we would be glad to provide trips to foreign astronauts,” said Yang Liwei, deputy director of China Manned Space Agency, in a report from China Daily.
Launch of Shenzhou 7. Credit: PR China
“We will also welcome foreign astronauts who have received our training to work in our future space station.”
Yang’s remarks came at the United Nations/China Workshop on Human Space Technology. The director also pointed out that European astronauts have visited the Chinese facilities, and vice versa, which could point the way forward to more work between the nations.
China’s most recent spaceflight took place in June. Shenzhou 10 docked with a small space station in orbit (Tiangong-1.) The country is reportedly planning a larger space station in the coming years and possibly, some manned lunar missions.
Abigail Harrison just prior to the launch of her mentor astronaut, Luca Parmitano, in Kazakhstan May 28, 2013. Credit: Abigail Harrison
Meet Abigail Harrison. This teenager’s enthusiasm about space so impressed Luca Parmitano — who just happens to be a European Space Agency astronaut on the space station right now — that the two have a social media collaboration going.
Abby collects questions from readers of her blog (AstronautAbby.com) and sends them up to the station for Parmitano to read and respond to.
Parmitano’s first mission in space, which he calls Volare (“Fly”), has been a busy one. He’s driven a rover, practiced grappling techniques for the Cygnus spacecraft — which was delayed in its docking to Tuesday (now Saturday) — and experienced two spacewalks (one went to plan, and the other was cut short due to a spacesuit leak).
Meanwhile, Abby had a space-y summer of her own. She fundraised thousands of dollars to see Parmitano’s launch in May. Then she went to Space Camp and toured several NASA and international agency centers. We caught up with Abby to find out how things are going — and if this brings her any closer to her dream of going to space herself. Below is a slightly edited e-mail conversation about her adventures.
Universe Today: How’s it going with the partnership?
Abigail Harrison: Working with Luca has been a lot of fun! I have really enjoyed being able to e-mail with him on station and especially the opportunity I had to talk to him while visiting Marshall Space Flight Center in Huntsville, AL at the end of July. The AstronautAbby community has been very active sharing images of the Space Station flying by for my #CatchLuca weekly blog post, and the #AskLuca questions submitted by my community have been great. It’s fun to hear how Luca answers these questions each week.
UT: What are the best things that you have been doing specifically to spread the message of Volare?
AH: I think my #CatchLuca blog series has been a real hit! So many people from around the world have taken photos of the ISS passing overhead and decided to submit them and share with the world. It’s been great! I think this helps to spread the message as it is people on Earth getting excited about the space station and sharing their own pictures. The more sharing that happens, the more aware people get about the mission and the more they learn.
Luca Parmitano, a European Space Agency astronaut, is on his first voyage to space as a part of Expeditions 36/37. Credit: NASA
The #AskLuca series has also been very successful. It’s true, anyone can jump on social media and ask a question of Luca or any astronaut and they most likely will answer it, but this series has allowed people who may not be socially savvy to ask questions, as well as people to ask longer questions. The fact that all the answers are published on my blog is also great as people can read it in a published article versus on a social media update.
UT: Tell us more about these NASA tours you’ve been doing lately. What is your goal in doing them?
AH: I have been fortunate to be in the right places at the right time. This summer I was in Houston for a gymnastics camp, and therefore I was able to tour the Johnson Space Center – but not just tour the center, I got to see the Neutral Buoyancy Lab and compare it to the Russian counterpart that I saw in May during my visit to Star City [astronaut training complex in Russia] when attending Luca’s launch. I also was able to go on the floor of Mission Control and see a specialized robotics lab, along with a lot of other cool things.
Abigail Harrison simulates repairing a satellite during Space Camp in Huntsville, AL. Credit: Abigail Harrison
After Houston, I headed to Huntsville for Space Camp. While in Huntsville I was able to tour the Marshall Space Flight Center and specifically see some of the work NASA is doing along with ATK to build the Space Launch System, which is the rocket system that will take me to Mars someday (similar but much bigger than the Saturn V rockets that took Apollo to the moon).
Finally, I visited Lockheed Martin’s facilities in Colorado to see the production of the Orion, which is the spacecraft currently being developed to go to Mars, the moon and asteroids. These visits have tremendous value as I have been able to share pictures, write about the visits and talk about what I have seen with people everywhere.
The goal is to learn about what is being done right now to realize the future American missions to Mars, the moon and asteroids and continue human space flight. The more I learn and understand about our current efforts to realize the future of human space exploration, the easier it is for me to talk about the future and educate the general public. Part of my mission is to help spread the word to people around the world about the future of human space flight and get the public excited for what we will do next.
Abigail Harrison with subscale test rocket motors during a visit to the Marshall Space Flight Center in Huntsville, AL. Credit: Abigail Harrison
UT: I’m sure you’ve been talking to Luca regularly. What do you talk about?
AH: We e-mail and tweet quite a bit. We have only talked once. To be honest, I follow his mission very closely through his online updates and ESA and NASA updates for my role as his Earth Liaison, and therefore I am up to date on what he is doing, probably more up to date than most people.
When we e-mail and talk it is usually about other things like advice on school, travel (he lives in Houston so gave me some good tips on what to see while visiting), and generally asking him how he is doing and what it is like to live and work on the ISS. It’s not that different from when he was training for his mission on Earth, except for now he is flying in space overhead and his e-mails and tweets come from space. 🙂
UT: Do you feel any closer to being in space as a result of this partnership?
AH: Yes, I do. How could I not? I would guess that anyone who personally knows an astronaut living on the ISS would feel closer to being in space. The personal connection means you are paying close attention to everything the astronaut is doing, and following the mission very closely.
The fact that I am sharing so much of what Luca is doing as part of my role as his Earth Liaison also helps me feel closer to being in space, because I am sharing with so many people and they in turn offer me support everyday towards my goals. I watch Luca and can imagine the day when it’s my turn to go into space. It’s been an incredible experience to get to be part of his mission.
Finally, we had clear skies for a terrific Virtual Star Party. Match this with the amazing new high-definition resolution of Google+ Hangouts on Air, and you’ve got a match made in heaven. Astronomers joined us from the West Coast, the East Coast and even Europe.
But the technology gods wouldn’t let these gifts go unpunished. Almost every one of the astronomers wrestled with some kind of technical gremlin.
But if you want to see the Moon and Jupiter in high definition, this was the star party to watch.
We have a Virtual Star Party every Sunday night on Google+ when it gets dark on the West Coast. Currently, that’s about 8 pm Pacific / 11 pm Eastern. We’ll broadcast a live view of the night sky from multiple telescopes across the world.
Subscribe to our YouTube Channel to get notified when there are new parties going live.
After launching to orbit atop the Antares rocket on Sept. 18, the first ever Cygnus cargo spacecraft is chasing the ISS and set to dock on Sept 22. Until then you may be able to track it in the night skies. Here is full scale, high fidelity mockup of Cygnus to give a feel for its size being similar to a small room. Credit: Ken Kremer (kenkremer.com)
After launching to orbit atop the Antares rocket on Sept. 18, the first ever Cygnus cargo spacecraft is chasing the ISS and set to dock on Sept 22. Until then you have the opportunity to track it in the night skies. This full scale, high fidelity mockup of the Orbital Sciences/Thales Alenia Cygnus gives a feel for it being similar in size to a small room. Credit: Ken Kremer (kenkremer.com) Story Updated: Further details and photos – and NASA TV link to Live Docking Coverage [/caption]
WALLOPS ISLAND, VA – Following Wednesday morning’s (Sept. 18) spectacular blastoff of the Antares rocket with the commercial Cygnus resupply spacecraft, sky watchers now have a very limited window of opportunity to spot the maiden Cygnus chasing down the International Space Station (ISS) in the early morning skies before it arrives for the historic 1st rendezvous and docking on Sunday morning, Sept 22.
So between now and early Sunday you have the chance to gaze skywards and see and photograph history’s first Earth orbiting Cygnus hunting the ISS and gradually close in for the delicate coupling maneuver.
Here’s our guide on ‘How to Spot Cygnus’.
Sighting opportunities are available worldwide from at least North and South America, Europe, Asia and Africa according to NASA’s ‘Spot the Station’ website – here. See more websites listed below.
Update 4 a.m. Sunday Sept 22– Cygnus Rendezvous Delayed 48 Hours due to communications glitch Update Sept 23: delayed to no earlier than Saturday due to Soyuz launch on Wednesday. Thus more chances to view!
Time is of the essence! So don’t delay to check this out!
Since the successful separation of the first Cygnus – built by Orbital Sciences and Thales Alenia – from Antares, the Earth orbiting vehicle has been successfully firing its hydrazine fueled thrusters to move ever closer to the massive orbiting lab complex – at a rate of 82 statute miles per orbit..
Artist rendering of Cygnus spacecraft approaching the International Space Station
If all of the ten on orbit maneuvering tests proceed satisfactorily, Cygnus will reach the vicinity of the station on Sunday early morning (US East Coast time).
“There are some ‘goodies’ stowed on board for the crew’s enjoyment,” Alan Lindenmoyer, NASA’s program manager for commercial crew and cargo, told Universe Today at NASA Wallops.
ISS astronauts Karen Nyberg (NASA) and Luca Parmitano (ESA) are scheduled to grapple Cygnus with the station’s Canadian built robotic arm between 7:15 and 7:30 a.m. EDT, if all goes well.
Nyberg and Parmitano, working at a robotic work station in the Cupola module, are due to install the cargo carrier at an earth facing docking port on the Harmony pressurized module as early as 9 a.m. EDT, Sept 22.
Antares rocket lifts off at 10:58 a.m. EDT Sept 18 with commercial Cygnus cargo resupply ship bound for the International Space Station (ISS) from Mid-Atlantic Regional Spaceport Pad-0A at NASA’s Wallops Flight Facility in Virginia. Credit: Ken Kremer (kenkremer.com)
It’s the same docking port already used by the SpaceX Dragon cargo vessel on three successful missions to date since 2012.
Cameras on the second stage captured this amazing image of the Cygnus spacecraft separating from the rocket into orbit.Although Cygnus is much smaller than the ISS, it should still be visible – weather permitting of course.
At 17 feet (5 meters) long and 10 feet (3 meters) wide, Cygnus is the size of a small room.
In fact, while I was at NASA Wallops this week reporting on the Antares launch for Universe Today, I had a chance to visit a full scale, high fidelity mockup of Cygnus built for Orbital Sciences and on display at the local community center in Chincoteague, VA.
The Cygnus display model gives one a great feel for just how big Cygnus really is- see my photos herein.
Front view showing docking mechanism and hatch of Cygnus module in this full scale, high fidelity mockup of the Orbital Sciences/Thales Alenia spacecraft gives a feel for it being similar in size to a small room. Credit: Ken Kremer (kenkremer.com)
A full size human mannequin standing inside showed that a human can fit comfortably inside.
Thales Alenia Space in Italy designed and constructed the 17 foot ( 5 meter) long Cygnus pressurized module under contract with Orbital.
“Thales Alenia has actually built 50% of the pressurized modules currently comprising the ISS,” said Luigi Quaglino, Thales Alenia Senior Vice President.
“We have built 25 pressurized space modules and learned a lot along the way,” Quaglino told Universe Today at NASA Wallops.
The ISS is the largest manmade object in orbit. It’s the size of a football field and the brightest object in the night sky after the Moon thanks also to the huge, reflecting solar arrays.
Cygnus will be significantly dimmer, but nevertheless should be readily visible.
Look for a ‘star’ moving gradually against the backdrop of stars trailing behind the ISS that likewise appears as a bright moving ‘star’.
ISS streaks over Princeton, NJ – time lapse image. Credit: Ken Kremer
As Sunday approaches, the gap between the ISS and Cygnus narrows.
On Thursday Cygnus was trailing about 10 minutes behind the ISS. Whereas on Friday and Saturday, the gap narrows down to roughly 4 minutes and then just 1 minute.
You can also try and photograph the ISS and Cygnus trails by mounting your camera on a tripod and leaving the shutter open at least several seconds and longer. Send me any cool time lapse photos to post here at Universe Today.
Many folks have never seen an ISS flyover and this is a fantastic time to start as the dynamic duo speed merrily across the nighttime sky.
To determine if there are any favorable sighting opportunities in your area, check out NASA’s Spot the Station website – here.
Check the NASA website for a detailed listing of the precise times, elevations, direction and durations. It’s an easy to use viewing guide. Just plug in the particulars of the country in which you live.
And Orbital Sciences reports that “AGI has developed a slick interactive 2D/3D simulation that allows you to track the location of Cygnus in real-time.”
I have personally watched the SpaceX Dragon, European ATV and Japanese HTV cargo carriers streaking through the night sky, trailing a few minutes behind the ISS. And it’s always a thrill.
The cargo vessel will deliver about 1,300 pounds (589 kilograms) of cargo, including food, clothing, water, science experiments, spare parts and gear to the Expedition 37 crew.
Cygnus will remain attached to the ISS for about a month. The astronauts will unload the supplies including few goodies starting on Monday. They they’ll pack it with trash. After undocking Cygnus will come to a flaming finale by burning up upon reentry into the Earth’s atmosphere.
So there should be a final opportunity to view it circling Earth.
NASA Television coverage of the arrival and capture of Cygnus will begin at 4:30 a.m. EDT
Streaming video will be available on NASA’s website at http://www.nasa.gov/ntv
Saturday evening Update:
NASA has given the GO for Sunday morning Docking !
Learn more about Cygnus, Antares, LADEE, Curiosity, Mars rovers, MAVEN, Orion and more at Ken’s upcoming presentations
Oct 3: “Curiosity, MAVEN and the Search for Life on Mars – (3-D)”, STAR Astronomy Club, Brookdale Community College & Monmouth Museum, Lincroft, NJ, 8 PM
Oct 8: NASA’s Historic LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Princeton University, Amateur Astronomers Assoc of Princeton (AAAP), Princeton, NJ, 8 PM
1st operational Cygnus pressurized cargo module from Orbital Sciences Corp. & Thales Alenia Space sits inside high bay clean room facility at NASA Wallops Flight Facility, VA for preflight processing. This Cygnus spacecraft arrived from Italy and may launch to the ISS as early as December 2013 from Wallops launch pad 0A. Credit: Ken Kremer (kenkremer.com)Ken Kremer (Universe Today) and Antares rocket at NASA Wallops Launch Complex 0A. Credit: Ken Kremer
It’s Friday so it’s space hangout time. Join Universe Today publisher Fraser Cain and a crew of space journalists as they discuss the big stories of the week. We’ve got the launch of the Antares rocket, a freaked out armadillo, an unexpected end to Deep Impact, ISON conspiracy madness, and more. We were joined by our regulars, but it was Elizabeth Howell’s first time. She’s been a long-time contributor to Universe Today, but this was the first time she’s joined the Weekly Space Hangout.
Host: Fraser Cain
Commentary: Amy Shira Teitel, David Dickinson, Elizabeth Howell, Jason Major
We record the Weekly Space Hangout every Friday afternoon at 12:00 Pacific, 3:00 Eastern, or 20:00 GMT. You can watch it live on Google+ or on Universe Today. You can also get the audio version within the 365 Days of Astronomy Podcast.
Aurorae dance across the sky and among the clouds over Norway on September 28, 2013. Credit and copyright: Frank Olsen.
Frank Olsen reports that the weather in arctic part of Norway has been fantastic lately. Even so, the aurora are starting to make nightly appearances.
“I was standing on the very tip of an island in Vesterålen with a spectacular view, looking out on the Atlantic ocean,” he said. “With the full moon behind me, the clouds were amazing.”
Clouds mixed in with the aurora made for some lovely views. In all, Frank said he nabbed almost 400 images on his memory card! See another shot, below.
Aurora among the clouds at twilight in Norway on September 18, 2013. Credit and copyright: Frank Olsen.
As we’ve said previously, these gorgeous sights must be payback for enduring the long winters in northern Norway. You can see more of Frank’s beautiful imagery of aurora, the night sky and more at his Flickr page, his website (he has prints for sale) or his Facebook page.
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.
Comet Tempel 1 a minute after being struck by Deep Impact's impactor on July 4, 2005 (NASA/JPL-Caltech/UMD)
After almost 9 years in space that included an unprecedented July 4th impact and subsequent flyby of a comet, an additional comet flyby, and the return of approximately 500,000 images of celestial objects, NASA’s Deep Impact/EPOXI mission has officially been brought to a close.
The project team at NASA’s Jet Propulsion Laboratory has reluctantly pronounced the mission at an end after being unable to communicate with the spacecraft for over a month. The last communication with the probe was Aug. 8. Deep Impact was history’s most traveled comet research mission, having journeyed a total of about 4.7 billion miles (7.58 billion kilometers).
“Deep Impact has been a fantastic, long-lasting spacecraft that has produced far more data than we had planned,” said Mike A’Hearn, the Deep Impact principal investigator at the University of Maryland in College Park. “It has revolutionized our understanding of comets and their activity.”
Artist’s rendering of the Deep Impactor flyby spacecraft (NASA)
Launched in January 2005, the spacecraft first traveled about 268 million miles (431 million kilometers) to the vicinity of comet Tempel 1. On July 3, 2005, the spacecraft deployed an impactor into the path of comet to essentially be run over by its nucleus on July 4. This caused material from below the comet’s surface to be blasted out into space where it could be examined by the telescopes and instrumentation of the flyby spacecraft. Sixteen days after that comet encounter, the Deep Impact team placed the spacecraft on a trajectory to fly back past Earth in late December 2007 to put it on course to encounter another comet, Hartley 2 in November 2010, thus beginning the spacecraft’s new EPOXI mission.
“Six months after launch, this spacecraft had already completed its planned mission to study comet Tempel 1,” said Tim Larson, project manager of Deep Impact at JPL. “But the science team kept finding interesting things to do, and through the ingenuity of our mission team and navigators and support of NASA’s Discovery Program, this spacecraft kept it up for more than eight years, producing amazing results all along the way.”
The spacecraft’s extended mission culminated in the successful flyby of comet Hartley 2 on Nov. 4, 2010. Along the way, it also observed six different stars to confirm the motion of planets orbiting them, and took images and data of the Earth, the Moon and Mars. These data helped to confirm the existence of water on the Moon, and attempted to confirm the methane signature in the atmosphere of Mars. One sequence of images is a breathtaking view of the Moon transiting across the face of Earth.
This image of comet ISON C/2012 S1 from NASA’s Deep Impact/EPOXI spacecraft clearly shows the coma and nucleus on Jan. 17 and 18, 2013 beyond the orbit of Jupiter. Credit: NASA.
After losing contact with the spacecraft last month, mission controllers spent several weeks trying to uplink commands to reactivate its onboard systems. Although the exact cause of the loss is not known, analysis has uncovered a potential problem with computer time tagging that could have led to loss of control for Deep Impact’s orientation. That would then affect the positioning of its radio antennas, making communication difficult, as well as its solar arrays, which would in turn prevent the spacecraft from getting power and allow cold temperatures to ruin onboard equipment, essentially freezing its battery and propulsion systems.
Without battery power, the Deep Impact spacecraft is now adrift and silent, spinning out of control through the solar system.
Launch of Deep Impact aboard a Boeing Delta II rocket from Cape Canaveral AFS on Jan. 12, 2005 (NASA)
“Despite this unexpected final curtain call, Deep Impact already achieved much more than ever was envisioned. Deep Impact has completely overturned what we thought we knew about comets and also provided a treasure trove of additional planetary science that will be the source data of research for years to come.”
– Lindley Johnson, Program Executive for the Deep Impact mission
It’s a sad end for a hardworking spacecraft, but over the course of its 8 1/2 years in space Deep Impact provided many significant results for the science community. Here are the top five, according to the mission’s principal investigator Michael A’Hearn.
Curiosity Rover snapped this self portrait mosaic with the MAHLI camera while sitting on flat sedimentary rocks at the “John Klein” outcrop where the robot conducted historic first sample drilling inside the Yellowknife Bay basin, on Feb. 8 (Sol 182) at lower left in front of rover. The photo mosaic was stitched from raw images snapped on Sol 177, or Feb 3, 2013, by the robotic arm camera - accounting for foreground camera distortion. Credit: NASA/JPL-Caltech/MSSS/Marco Di Lorenzo/KenKremer (kenkremer.com).
NASA’s Mars Curiosity rover can’t find any sign of methane on the red planet, but the agency emphasized that methane would be only one indicator of possible life. There could be others.
“It reduces the probability of current methane-producing Martian microbes, but this addresses only one type of microbial metabolism,” stated Michael Meyer, NASA’s lead scientist for Mars exploration. “As we know, there are many types of terrestrial microbes that don’t generate methane.”
Curiosity (which can look for habitable conditions, but not life itself) sniffed the atmosphere six times for methane between October 2012 and June 2013. It didn’t see any sign of the molecule, which has been detected in other parts of Mars. The instrument being used, the tunable laser spectrometer, would be able to detect minute concentrations. Scientists today estimate methane on Mars must be 1.3 parts per billion at the most, which is only one-sixth as much as earlier estimates.
This image shows concentrations of Methane reported on Mars in 2009, from an Earth-based observatory. Credit: NASA
On Thursday, NASA pointed out that reports of the highest concentrations of Mars methane came from Earth-based observatories, which seems to imply that they think peering through Earth’s atmosphere may have distorted the measurements. Some Earthly measurements indicated local regions with methane as high as 45 parts per billion.
“There’s no known way for methane to disappear quickly from the atmosphere,” stated Sushil Atreya, a professor of atmospheric and space science at the University of Michigan, Ann Arbor.
“Methane is persistent. It would last for hundreds of years in the Martian atmosphere. Without a way to take it out of the atmosphere quicker, our measurements indicate there cannot be much methane being put into the atmosphere by any mechanism, whether biology, geology, or by ultraviolet degradation of organics delivered by the fall of meteorites or interplanetary dust particles.”
Researchers estimate only 10 to 20 tons per year of methane enter the atmosphere of Mars, which is 50 million times less than what occurs on Earth. You can read more details in the paper in Science Express.
What do you think is happening? Leave your ideas in the comments.
Over the course of a 26,000 year cycle, the Earth’s axis traces out a great circle in the sky. This is known as the precession of the equinoxes. 
