Posted on by Nancy Atkinson

“This Week in Space” with Miles O’Brien Debuts

This Week In Space from Spaceflight Now on Vimeo.

The same team that recently has been providing innovative live online coverage of space shuttle launches is now “airing” a weekly space news round-up show. “This Week in Space” is hosted by former CNN anchor and space correspondent Miles O’Brien. It also features veteran journalist David Waters, and is brought to you via Spaceflightnow.com.

I had the chance to chat with Miles briefly a while ago, and asked him if this was the type of space coverage he had always wanted to do. He said, “Yes, definitely! I am enjoying this immensely.” His enthusiasm is obvious in this new online show.
Continue reading ““This Week in Space” with Miles O’Brien Debuts”

Posted on by Ken Kremer

Soyuz Blasts off with International Crew to build out ISS

The Expedition 22 crew poses for a group snapshot while visiting the Soyuz launch vehicle assembly facility in front of the rocket's third stage. Crew members are, from the left, Russian cosmonaut Oleg Kotov, Soyuz commander; NASA astronaut T.J. Creamer, flight engineer; and Japan Aerospace Exploration Agency astronaut Soichi Noguchi, flight engineer. Photo credit: NASA/Victor Zelentsov


An international crew of three astronauts and cosmonauts blasted off Sunday (Dec 20) at 4:52 PM EST in a Russian capsule from the bone chilling Baikonur Cosmodrome in Kazakhstan, bound for the International Space Station (ISS). The crew aboard the Soyuz TMA-17 capsule comprises Russian cosmonaut Oleg Kotov, NASA’s T.J. Creamer, and Soichi Noguchi of the Japan Aerospace Exploration Agency.

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Following a two day pursuit they will rendezvous and link up with the ISS at the Zarya module’s nadir port on Tuesday at 5:58 p.m. EST about 220 miles over South America. Then they will officially join the Expedition 22 core crew of two, ISS Commander Jeff Williams (NASA) and flight engineer Max Suraev (Russia) thereby enlarging the orbiting outposts population to five, just one person shy of the full staffing of six.

Williams and Sureav have served as the sole occupants for the last three weeks since the scheduled Dec. 1 departure of the three man Expedition 21 crew. They arrived by Soyuz capsule TMA-16 in October.

Hatches between the ISS and Soyuz will be opened about 90 minutes after the Tuesday docking, which will be carried live on NASA TV. Kotov, Creamer and Noguchi are bringing along holiday goodies just in time to celebrate the arrival of Christmas and begin their 6 month stint in space.

The pre-dawn launch occurred precisely on time at 3:52 a.m. Monday local Kazakh time and was timed to coincide with the moment Earth’s rotation carried the launch pad into the plane of the space station’s orbit. The roaring stream of flames lit up the night sky for earth bound observers for miles around.

With Soyuz Commander Kotov occupying the center seat, the capsule separated from the third stage after the thunderous 9 minute climb to space. “Everyone feels great, no problems”, Kotov reported as the capsule was safely injected into an initial earth orbit. A live internal video feed showed the crew for most of the ride to orbit, working efficiently and in a relaxed manner. Engines will be fired three more times to raise the orbit and maneuver the capsule to match the stations orbit. On Tuesday the engines will be fired for a final time to align the Soyuz for docking.

The Expedition 22 crew of five have a busy agenda ahead filled with spacewalks, shuttle arrivals, relocating equipment, attachment of new modules and ambitious science experiments

Expedition 22 Soyuz Rollout. Credit: NASA/Bill Ingalls
Expedition 22 Soyuz Rollout. Credit: NASA/Bill Ingalls

This was the first December lift off for a Soyuz since 1990 and took place in the frigid cold as the earthling observers shivered outside. The crew had been training in Baikonur for the last week and a half to complete final launch preparations.

The launch pad is the very same one used to support the historic launch of Cosmonaut Yuri Gagarin in 1961 on mankind’s first manned space flight. The Soyuz crew capsule has been in use by Russia since 1967.
Creamer is making his first space flight and is a distinguished Army aviator. This is Kotov’s 2nd flight to the ISS where he has already performed two spacewalks. Likewise it’s the 2nd flight for Noguchi, but his first on board a Soyuz. He was previously a member of the Shuttle Return to Flight crew in 2005. Three dozen Japanese journalists were on hand to document the mission, the first by a Japanese aboard a Soyuz.

Before today’s lift-off, Bill Gerstenmaier, NASA Administrator for NASA Associate Administrator for Space Operations previewed the ‘year in space’ to come. “It’s an amazing time in spaceflight. We are bringing the station crew back up to five and learning how to operate with a larger crew size. For the systems to work right that requires a lot of preparation”.

“This will be an amazing year upcoming as I stand here in Kazakhstan with the Soyuz behind me. We have a shuttle almost ready to fly from KSC and this Soyuz set to fly. 2010 will be a busy year. We’ll have as many as 6 Progress, 4 Soyuz and 5 Shuttle flights to the ISS. The shuttle will start the year by bringing up the Tranquility and Cupola modules” (read our previous article for more info).

“We have built a phenomenal research station in space which could only have been assembled by the shuttle. But now it’s time to move beyond the shuttle. After the shuttle retires we will transition to smaller rockets like the Soyuz and the Dragon”.

Posted on by Fraser Cain

Planets Fact Sheet

Mercury
Mass: 0.3302 x 1024 kg
Volume: 6.083 x 1010 km3
Average radius: 2439.7 km
Average diameter: 4879.4 km
Mean density: 5.427 g/cm3
Escape velocity: 4.3 km/s
Surface gravity: 3.7 m/s2
Visual magnitude: -0.42
Natural satellites: 0
Rings? – No
Semimajor axis: 57,910,000 km
Orbit period: 87.969 days
Perihelion: 46,000,000 km
Aphelion: 69,820,000 km
Mean orbital velocity: 47.87 km/s
Maximum orbital velocity: 58.98 km/s
Minimum orbital velocity: 38.86 km/s
Orbit inclination: 7.00°
Orbit eccentricity: 0.2056
Sidereal rotation period: 1407.6 hours
Length of day: 4222.6 hours
Discovery: Known since prehistoric times
Minimum distance from Earth: 77,300,000 km
Maximum distance from Earth: 221,900,000 km
Maximum apparent diameter from Earth: 13 arc seconds
Minimum apparent diameter from Earth: 4.5 arc seconds
Maximum visual magnitude: -1.9

Venus
Mass: 4.8685 x 1024 kg
Volume: 92.843 x 1010 km3
Average radius: 6051.8 km
Average diameter: 12103.6 km
Mean density: 5.243 g/cm3
Escape velocity: 10.36 km/s
Surface gravity: 8.87 m/s2
Visual magnitude: -4.40
Natural satellites: 0
Rings? – No
Semimajor axis: 108,210,000 km
Orbit period: 224.701 days
Perihelion: 107,480,000 km
Aphelion: 108,940,000 km
Mean orbital velocity: 35.02 km/s
Maximum orbital velocity: 35.26 km/s
Minimum orbital velocity: 34.79 km/s
Orbit inclination: 3.39°
Orbit eccentricity: 0.0067
Sidereal rotation period: 5832.5 hours
Length of day: 2802.0 hours
Discovery: Known since prehistoric times
Minimum distance from Earth: 38,200,000 km
Maximum distance from Earth: 261,000,000 km
Maximum apparent diameter from Earth: 66.0 arc seconds
Minimum apparent diameter from Earth: 9.7 arc seconds
Maximum visual magnitude: -4.6

Earth
Mass: 5.9736 x 1024 kg
Volume: 108.321 x 1010 km3
Average radius: 6,371.0 km
Average diameter: 12,742 km
Mean density: 5.515 g/cm3
Escape velocity: 11.186 km/s
Surface gravity: 9.798 m/s2
Visual magnitude: -3.86
Natural satellites: 1
Rings? – No
Semimajor axis: 149,600,000 km
Orbit period: 365.256 days
Perihelion: 147,090,000 km
Aphelion: 152,100,000 km
Mean orbital velocity: 29.78 km/s
Maximum orbital velocity: 30.29 km/s
Minimum orbital velocity: 29.29 km/s
Orbit inclination: 0.00°
Orbit eccentricity: 0.0167
Sidereal rotation period: 23.9345 hours
Length of day: 24.0000 hours
Axial tilt: 23.45°

Mars
Mass: 0.64185 x 1024 kg
Volume: 16.318 x 1010 km3
Average radius: 3,389.5 km
Average diameter: 6,779 km
Mean density: 3.933 g/cm3
Escape velocity: 5.03 km/s
Surface gravity: 3.71 m/s2
Visual magnitude: -1.52
Natural satellites: 2
Rings? – No
Semimajor axis: 227,920,000 km
Orbit period: 686.980 days
Perihelion: 206,620,000 km
Aphelion: 249,230,000 km
Mean orbital velocity: 24.13 km/s
Orbit inclination: 1.850°
Orbit eccentricity: 0.0935
Sidereal rotation period: 24.6229 hours
Length of day: 24.6597 hours
Axial tilt: 25.19 °
Discovery: Known since prehistoric times
Minimum distance from Earth: 55,700,000 km
Maximum distance from Earth: 401,300,000 km
Maximum apparent diameter from Earth: 25.1 arc seconds
Minimum apparent diameter from Earth: 3.5 arc seconds
Maximum visual magnitude: -2.91

Jupiter
Mass: 1,898.6 x 1024 kg
Volume: 143,128 x 1010 km3
Average radius: 69,911 km
Average diameter: 139,822 km
Mean density: 1.326 g/cm3
Escape velocity: 59.5 km/s
Surface gravity: 24.79 m/s2
Natural satellites: 63
Rings? – Yes
Semimajor axis: 778,570,000 km
Orbit period: 4,332.589 days
Perihelion: 740,520,000 km
Aphelion: 816,620,000 km
Mean orbital velocity: 13.07 km/s
Orbit inclination: 1.304°
Orbit eccentricity: 0.0489
Sidereal rotation period: 9.9250 hours
Length of day: 9.9259 hours
Axial tilt: 3.13°
Discovery: Known since prehistoric times
Minimum distance from Earth: 588,500,000 km
Maximum distance from Earth: 968,100,000 km
Maximum apparent diameter from Earth: 50.1 arc seconds
Minimum apparent diameter from Earth: 29.8 arc seconds
Maximum visual magnitude: -2.94

Saturn
Mass: 568.46 x 1024 kg
Volume: 82,713 x 1010 km3
Average radius: 58,232 km
Average diameter: 116,464 km
Mean density: 0.687 g/cm3
Escape velocity: 35.5 km/s
Surface gravity: 10.44 m/s2
Natural satellites: 60
Rings? – Yes
Semimajor axis: 1,433,530,000 km
Orbit period: 10,759.22 days
Perihelion: 1,352,550,000 km
Aphelion: 1,514,500,000 km
Mean orbital velocity: 9.69 km/s
Orbit inclination: 2.485°
Orbit eccentricity: 0.0565
Sidereal rotation period: 10.656 hours
Length of day: 10.656 hours
Axial tilt: 26.73°
Discovery: Known since prehistoric times
Minimum distance from Earth: 1,195,500,000 km
Maximum distance from Earth: 1,658,500,000 km
Maximum apparent diameter from Earth: 20.1 arc seconds
Minimum apparent diameter from Earth: 14.5 arc seconds
Maximum visual magnitude: 0.43

Uranus
Mass: 86.832 x 1024 kg
Volume: 6,833 x 1010 km3
Average radius: 25,362 km
Average diameter: 50,724 km
Mean density: 1.270 g/cm3
Escape velocity: 21.3 km/s
Surface gravity: 8.87 m/s2
Natural satellites: 27
Rings? – Yes
Semimajor axis: 2,872,460,000 km
Orbit period: 30,685.4 days
Perihelion: 2,741,300,000 km
Aphelion: 3,003,620,000 km
Mean orbital velocity: 6.81 km/s
Orbit inclination: 0.772°
Orbit eccentricity: 0.0457
Sidereal rotation period: 17.24 hours
Length of day: 17.24 hours
Axial tilt: 97.77°
Discovery: 13 March 1781
Minimum distance from Earth: 2,581,900,000 km
Maximum distance from Earth: 3,157,300,000 km
Maximum apparent diameter from Earth: 4.1 arc seconds
Minimum apparent diameter from Earth: 3.3 arc seconds
Maximum visual magnitude: 5.32

Neptune
Mass: 102.43 x 1024 kg
Volume: 6,254 x 1010 km3
Average radius: 24,622 km
Average diameter: 49,244 km
Mean density: 1.638 g/cm3
Escape velocity: 23.5 km/s
Surface gravity: 11.15 m/s2
Natural satellites: 13
Rings? – Yes
Semimajor axis: 4,495,060,000 km
Orbit period: 60,189 days
Perihelion: 4,444,450,000 km
Aphelion: 4,545,670,000 km
Mean orbital velocity: 5.43 km/s
Orbit inclination: 1.769°
Orbit eccentricity: 0.0113
Sidereal rotation period: 16.11 hours
Length of day: 16.11 hours
Axial tilt: 28.32°
Discovery: 23 September 1846
Minimum distance from Earth: 4,305,900,000 km
Maximum distance from Earth: 4,687,300,000 km
Maximum apparent diameter from Earth: 2.4 arc seconds
Minimum apparent diameter from Earth: 2.2 arc seconds
Maximum visual magnitude: 7.78

We’ve written many articles about the Solar System. Here’s an article about how many moons there are in the Solar System, and here’s an article about the formation of the Solar System.

If you’d like more info on the Solar System, check out NASA’s Planetary Fact Sheet.

We’ve recorded several episodes of Astronomy Cast about the Solar System. Start here, Episode 49: Mercury.

Posted on by Fraser Cain

Pluto Fact Sheet

Pluto's temperature makes it one of the coldest places in the Solar System.

The following Pluto fact sheet is based on NASA’s excellent planetary fact sheets. Pluto is no longer a planet, but a dwarf planet.

Mass: 0.0125 x 1024 kg
Volume: 0.715 x 1010 km3
Average radius: 1,195 km
Average diameter: 2,390 km
Mean density: 1.750 g/cm3
Escape velocity: 1.2 km/s
Surface gravity: 0.58 m/s2
Natural satellites: 3
Rings? – No
Semimajor axis: 5,906,380,000 km
Orbit period: 90,465 days
Perihelion: 4,436,820,000 km
Aphelion: 7,375,930,000 km
Mean orbital velocity: 4.72 km/s
Orbit inclination: 17.16°
Orbit eccentricity: 0.2488
Sidereal rotation period: 153.2928 hours
Length of day: 153.2820 hours
Axial tilt: 122.53°
Discovery: 18 February 1930
Minimum distance from Earth: 4,284,700,000 km
Maximum distance from Earth: 7,528,000,000 km
Maximum apparent diameter from Earth: 0.11 arc seconds
Minimum apparent diameter from Earth: 0.06 arc seconds
Maximum visual magnitude: 13.65

We’ve written many articles about Pluto for Universe Today. Here’s an article about why Pluto isn’t a planet any more, and here’s an article about the distance to Pluto.

If you’d like more info on Pluto, check out Hubblesite’s News Releases about Pluto, and here’s a link to NASA’s Solar System Exploration Guide to Pluto.

We’ve also recorded an entire episode of Astronomy Cast just about Pluto. Listen here, Episode 64: Pluto.

Posted on by Fraser Cain

Neptune Fact Sheet

Neptune

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The following Neptune fact sheet is based on NASA’s excellent planetary fact sheets. Neptune is the 8th planet from the Sun, and it requires a telescope to be able to see it.

Mass: 102.43 x 1024 kg
Volume: 6,254 x 1010 km3
Average radius: 24,622 km
Average diameter: 49,244 km
Mean density: 1.638 g/cm3
Escape velocity: 23.5 km/s
Surface gravity: 11.15 m/s2
Natural satellites: 13
Rings? – Yes
Semimajor axis: 4,495,060,000 km
Orbit period: 60,189 days
Perihelion: 4,444,450,000 km
Aphelion: 4,545,670,000 km
Mean orbital velocity: 5.43 km/s
Orbit inclination: 1.769°
Orbit eccentricity: 0.0113
Sidereal rotation period: 16.11 hours
Length of day: 16.11 hours
Axial tilt: 28.32°
Discovery: 23 September 1846
Minimum distance from Earth: 4,305,900,000 km
Maximum distance from Earth: 4,687,300,000 km
Maximum apparent diameter from Earth: 2.4 arc seconds
Minimum apparent diameter from Earth: 2.2 arc seconds
Maximum visual magnitude: 7.78

We’ve written many articles about Neptune for Universe Today. Here’s an article about the color of Neptune, and here’s an article about the atmosphere of Neptune.

If you’d like more info on Neptune, check out Hubblesite’s News Releases about Neptune, and here’s a link to NASA’s Solar System Exploration Guide to Neptune.

We’ve also recorded an entire episode of Astronomy Cast just about Neptune. Listen here, Episode 63: Neptune.

Posted on by Fraser Cain

Uranus Fact Sheet

Uranus, seen by Voyager 2. Image credit: NASA/JPL

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The following Uranus fact sheet is based on NASA’s excellent planetary fact sheets. Uranus is the 7th planet from the Sun, and it requires a telescope to be able to see it.

Mass: 86.832 x 1024 kg
Volume: 6,833 x 1010 km3
Average radius: 25,362 km
Average diameter: 50,724 km
Mean density: 1.270 g/cm3
Escape velocity: 21.3 km/s
Surface gravity: 8.87 m/s2
Natural satellites: 27
Rings? – Yes
Semimajor axis: 2,872,460,000 km
Orbit period: 30,685.4 days
Perihelion: 2,741,300,000 km
Aphelion: 3,003,620,000 km
Mean orbital velocity: 6.81 km/s
Orbit inclination: 0.772°
Orbit eccentricity: 0.0457
Sidereal rotation period: 17.24 hours
Length of day: 17.24 hours
Axial tilt: 97.77°
Discovery: 13 March 1781
Minimum distance from Earth: 2,581,900,000 km
Maximum distance from Earth: 3,157,300,000 km
Maximum apparent diameter from Earth: 4.1 arc seconds
Minimum apparent diameter from Earth: 3.3 arc seconds
Maximum visual magnitude: 5.32

We’ve written many articles about Uranus for Universe Today. Here’s an article about the atmosphere of Uranus, and here’s an article about a blue ring around Uranus.

If you’d like more info on Uranus, check out Hubblesite’s News Releases about Uranus. And here’s a link to the NASA’s Solar System Exploration Guide to Uranus.

We’ve also recorded an entire episode of Astronomy Cast just about Uranus. Listen here, Episode 62: Uranus.

Posted on by Fraser Cain

Saturn Fact Sheet

Saturn. Image credit: Hubble

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The following Saturn fact sheet is based on NASA’s excellent planetary fact sheets. Saturn is the 6th planet from the Sun, and the second largest planet in the Solar System.

Mass: 568.46 x 1024 kg
Volume: 82,713 x 1010 km3
Average radius: 58,232 km
Average diameter: 116,464 km
Mean density: 0.687 g/cm3
Escape velocity: 35.5 km/s
Surface gravity: 10.44 m/s2
Natural satellites: 60
Rings? – Yes
Semimajor axis: 1,433,530,000 km
Orbit period: 10,759.22 days
Perihelion: 1,352,550,000 km
Aphelion: 1,514,500,000 km
Mean orbital velocity: 9.69 km/s
Orbit inclination: 2.485°
Orbit eccentricity: 0.0565
Sidereal rotation period: 10.656 hours
Length of day: 10.656 hours
Axial tilt: 26.73°
Discovery: Known since prehistoric times
Minimum distance from Earth: 1,195,500,000 km
Maximum distance from Earth: 1,658,500,000 km
Maximum apparent diameter from Earth: 20.1 arc seconds
Minimum apparent diameter from Earth: 14.5 arc seconds
Maximum visual magnitude: 0.43

We’ve written many articles about Saturn for Universe Today. Here’s an article about the rotation of Saturn, and here’s an article about the atmosphere of Saturn.

If you’d like more info on Saturn, check out Hubblesite’s News Releases about Saturn. And here’s a link to the homepage of NASA’s Cassini spacecraft, which is orbiting Saturn.

We’ve also recorded an entire episode of Astronomy Cast just about Saturn. Listen here, Episode 59: Saturn.

Posted on by Nancy Atkinson

Review: SKYlaser 55 mW Green Laser Pointer

Have you ever been blown away by a laser? I just was! The folks at SKYlasers sent us a 55 mW Green Laser Pointer to try out. I’ve only ever used very small laser pointers before for indoor presentations, so I was completely unprepared for the power of this laser pointer. I literally felt like I could reach out and touch the Moon and stars!

This green laser pointer has a reported range of 80 km (50 miles.) The laser is easily visible in the day time too, well over 30 meters (100 feet,) — and likely even more — even in bright daylight, I discovered (see image at the bottom.)

SKYlaser laser pointers are about the size of a Sharpie pen. There is a clip to easily attach the laser pointer securely to a bag or shirt pocket (or pocket protector!) so it is easy to find when you’re outside and trying to point out a constellation or star to someone else.

The SKYlaser 55 mW laser package.
The SKYlaser 55 mW laser package.

These laser pointers are very easy to use: just put in 2 AAA batteries, push the button and the beam of light zooms out to space — well, not technically, since space is officially 100 km up – but SKYlasers has other higher powered laser pointers that actually do reach that threshold and beyond. But for all amateur or even professional astronomers wanting to point out any object in the night sky, this laser pointer will meet your needs. I’ve been at instructional astronomy viewing nights where the instructor’s laser pointer was difficult to see and it was hard to follow where the instructor was pointing. Not with this one! It produces a powerful beam that you can’t miss seeing!
Laser point keyswitch. Credit: SKYlasers.
Laser point keyswitch. Credit: SKYlasers.

The 55 mW green laser also has a key feature that can turn off the laser so it won’t turn on accidentally if the button gets pressed while in a pocket or bag. Other more powerful SKYlaser pointers have a key that can dim the beam, so if you do want to use it indoors, it won’t be over-powering.

The 55mW green laser I received retails for $129.99 USD, but SKYlasers has a whole range of green lasers from a 5mW at $39.99 to a 150mW at $299.99. Plus they have even more powerful red laser pointers and the super powerful infrared laser pointers. Some of these are so powerful that they even come with goggles. SKYlasers also has some portable lasers that are beyond what any average person or astronomer would need.

SKYlaser laser pointer at work at night. Photo: N. Atkinson
SKYlaser laser pointer at work at night. Photo: N. Atkinson

I would just like to point out that any of these laser pointers are not toys, so please treat them with all the necessary respect and safety precautions. They can sting skin and hurt your (or others) eyes. The 55 mW laser can burn through a black trashbag (yes, we actually tried this, and the bag started melting in about 15 seconds). Some of the more powerful ones can light matches, burn dark fabrics, etch dark plastics and leathers, light fireworks, or even melt rubber and plastics. Not sure why you’d want to do some of these things, but it points out how powerful they are. Of course, you also need to watch out for planes in the area when you are using them. If you are doing an astronomy activity with a large group where you might be easily distracted, I’d suggest appointing a “spotter” to keep on the lookout for airplanes that might come into the region.

But the SKYlaser green pointer is a great way to be able to share your love of astronomy with your friends and family. It would be a great gift for any astronomy buff.

For more information see the SKYlaser website.

See the green point of light on the tree trunk? The SKYlaser laser pointer is visible even in the daytime from over 30 meters (100 feet) -- and likely beyond. Photo: N. Atkinson
See the green point of light on the tree trunk? The SKYlaser laser pointer is visible even in the daytime from over 30 meters (100 feet) -- and likely beyond. Photo: N. Atkinson
Posted on by Fraser Cain

Why Are There So Many Celestron Reviews?

Collimation
Collimation

I’ve had a couple of readers write me, wondering what was going on with all the Celestron telescope reviews. Are we sponsored by Celestron, or something? Nope. Let me just make this clear. We don’t get any money from any of the telescope manufacturers, or any kind of sponsorship at all. If and when we do, I’ll let you know.

So far, Celestron, Vixen and Sky Watcher are the only telescope manufacturers willing to send out a telescope for us to review, and then willing to pay for the return shipping to take it back off our hands again. If I have to pay to receive a telescope, or ship it back, we can’t afford to review it on Universe Today.

I know that really sets the bar pretty low. Universe Today received almost 2 million visitors last month, with 50,000 people subscribed to the RSS feed and daily email newsletter. Many of them are very interested in owning a telescope and would love to read about all the telescopes on the market. But I’m honestly exhausted trying to justify this to the manufacturers.

But so we’re clear, we’re not paid to give Celestron good reviews. If Tammy comes across as kind of enthusiastic in her reviews, well… that’s Tammy; she’s an enthusiastic force of nature. The manufacturers pay to ship the telescopes to and from our reviewers (well, Tammy), and then I pay Tammy for her reviews. If the telescope companies advertise on Universe Today, through Google, or through direct advertising, it doesn’t influence what Tammy has to say about them.

And if you’re a telescope manufacturer who wants to join this elite club of companies getting reviews on Universe Today, you just need to pay for the shipping. And if you want to advertise on Universe Today, just drop me an email.

P.S. I picked up a Celestron First Scope for the, uh, kids, and I really like it. Thanks to Tammy for the review, and thanks to the IYA for helping get it built.

Posted on by Jerry Coffey

How Hot is Jupiter?

Jupiter in visible and infrared

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Given how far Jupiter is from the Sun, you might think that “how cold is Jupiter?” would be a more relevant question and you would be partially right. “How hot is Jupiter?” becomes more relevant the deeper into the planet’s atmosphere and core that you travel. Near the very center of the planet, scientists believe that temperatures can reach 35,500 C.

The outer edges of Jupiter’s atmosphere are much cooler than the core region. Temperatures in the atmosphere are thought to be as cold as -145 degrees C. The intense atmospheric pressure on Jupiter contributes to temperature increases as you descend. Not far into the atmosphere the pressure can be ten times what it is here on Earth and scientists speculate that the temperature is 20 degrees C(average room temperature on Earth). A few hundred km deeper into the planet and hydrogen becomes hot enough to turn into a liquid. The temperature at this point is believed to be over 9,700 C. The layer of dense molten hydrogen metal extends to the 78th percentile of the planet’s radius. Between the cold clouds and the molten lower regions is an interior atmosphere of hydrogen. The hydrogen in this region is at a temperature where there are no distinct liquid and gas phases, so the hydrogen is said to be in a supercritical fluid state.

The molten inner regions of the planet serve to heat the rest of the planet through convection, so Jupiter gives off more heat than it receives from the Sun. This heating prevents it from being an ice giant instead of a gas giant, but wreaks havoc in the atmosphere. Storms and high winds are generated by cool air and warm air mixing here on Earth. Scientist think that the same holds true on Jupiter. The Galileo spacecraft observed winds in excess of 600 kph. One difference is that the jet streams that drive storms and winds on Earth are caused by the Sun heating the atmosphere. On Jupiter it seems that the jet streams are driven by the planets’ own heat. Storms on Jupiter are as out-sized as the planet. The Great Red Spot is a single storm that has been raging for hundreds of years. Other storms have been observed to grow to more than 2,000 km in diameter in a single day.

“How hot is Jupiter?” is more relevant than you may have thought. The planet’s inner heat seems to be the basis for its identity as a stormy world. The actual temperatures of the different areas of the planet may not be a mystery much longer. Hopefully, the recently launched JUNO space mission will clear up many of the Jovian theories that scientists currently have.

We’ve written many articles about the temperature of planets for Universe Today. Here’s an article about how hot Mercury is, and here’s an article about how hot Venus is.

If you’d like more information on Jupiter, check out Hubblesite’s News Releases about Jupiter, and here’s a link to NASA’s Solar System Exploration Guide to Jupiter.

We’ve also recorded an episode of Astronomy Cast just about Jupiter. Listen here, Episode 56: Jupiter.

Sources:
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter
http://www.nasa.gov/mission_pages/juno/main/index.html