Uranus: A Guide to its 2013 Opposition

Credit:

Up for a challenge? Got a big 12” light bucket of a Dobsonian telescope and looking for something new to point it at? This week, as the Moon reaches New phase on October 4th and stays safely out of the late evening sky, why not check out Uranus and its retinue of moons. And yes, we’ve heard just about ALL the Uranus jokes —its pronounced yer-in-us, thank you very much — but feel free to attempt to pen an original if you must.

Now, back to astronomy. Uranus reaches opposition for 2013  on Thursday, October 3rd at 14:00 Universal Time. Opposition is the point in time that an outer planet rises as the Sun sets. In the case of Uranus, its opposition dates advance forward by about 4-5 days each year.

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The current location of Uranus in Pisces. Created by the author using Stellarium. (click to enlarge).

This also marks the start of the best time to hunt for the planet among the star fields of the constellation Pisces. Uranus will reach its maximum elevation above the southern horizon for northern hemisphere viewers for early October around local midnight. For observers south of the equator, Uranus will transit to the north. Incidentally, Uranus also currently sits near the equinoctial point occupied by the Sun during the March equinox, making viewing opportunities nearly equal for both hemispheres.

Uranus is 19.04 astronomical units distant during opposition 2013, or about 158 light minutes away. Shining at magnitude +5.8, Uranus presents a tiny blue-green disk just under 4” across at opposition.

Uranus currently lies six degrees SW of the +4.4 magnitude star Delta Piscium, on the border of the constellations Pisces and Cetus. Uranus will actually be crossing once again into the non-zodiacal constellation of Cetus later this year.

Discovered in 1781 by Sir William Herschel, Uranus has only completed 2 full orbits (2.75 to be precise) in its 84.3 year trips about the Sun. We can be thankful that William’s proposal to name the planet Geogium Sidus after his benefactor King George the III didn’t stick!

Starry Night Education
The path of Uranus into Cetus. Created by the author using Starry Night Education software.

At opposition, Uranus will be located at;

Right Ascension: 0h 40’

Declination: +3° 25’

Five of the 27 known moons of Uranus are also within the grasp of a moderate-sized backyard scope as well. The trick is to catch ‘em near greatest elongation, when they appear farthest from the “glare of Uranus” (hey, there’s a freebie for a snicker or two). An eyepiece equipped with an occulting bar, or simply nudging Uranus out of the field of view can also help.

With magnitudes ranging from +13 to +16, the moons of Uranus are similar in brightness to Neptune’s large moon Triton or the tiny world Pluto.

The five brightest moons of Uranus and their respective maximum elongations are:

Chart constructed by author.

And here’s a handy finder chart for the coming month, showing maximum elongations for each:

A corkscrew graph featuring the greatest elongations for the five brightest moons of Uranus. (Created by Ed Kotapish using PDS Rings Node).
A corkscrew graph featuring the greatest elongations for the five brightest moons of Uranus through October. (Created by Ed Kotapish using PDS Rings Node).

The first two moons were named Titania and Oberon by William’s son John after characters from William Shakespeare’s A Mid-Summer Night’s Dream. William discovered the first two moons of Uranus on the night of January 11th, 1787 using his 49.5” reflector. His scopes were so advanced for his day, that it wasn’t until over a half a century later that William Lassell discovered Umbriel and Ariel using the Liverpool Observatory’s 24” reflector in 1851.

Gerard Kuiper would later add tiny Miranda to the list, nabbing it with the McDonald Observatory’s 82” Otto Struve Telescope in 1948. We would then have to wait until Voyager 2’s 1986 flyby of Uranus in 1986 to add more. To date, Voyager 2 remains the only spacecraft to visit Uranus and Neptune.

The current convention established by the International Astronomical Union is to name the moons of Uranus after characters from the plays of Shakespeare or Alexander Pope’s Rape of the Lock.

There’s still a wide range of names in said literature to choose from!

It’s interesting to note that the orbits of the moons of Uranus are also currently tipped open about 25 degrees to our line of sight and widening. They were edge on in December 2007, and will be perpendicular to our Earthly view come 2029, after which they’ll head back to edge on in 2049. This is because Uranus and the orbits of its moons are tipped at a 97 degree angle relative to the planet’s orbit. This is why elongations for its moons are often quoted it terms of “north and south” of the planet, rather than the familiar east and west. Shadow transits of the moons can occur with about a year and a half during plane-crossing seasons, but they’re ~42 years apart and tough to spot on the tiny disk of Uranus!

October 4th Starry Night Education
An example of the orientation of Uranus’s moons on October 4th, with Oberon at greatest elongation. Note that Miranda is the tiny unlabeled moon with the interior orbit. (Created by the author using Starry Night Education software).

Uranus also reached aphelion in 2009 at 20.099 AU from the Sun —we’re still at the farther end of the spectrum, as oppositions of Uranus can range from 19.09 to 17.28 AU distant.

Uranus will rise earlier on each successive evening until it reaches quadrature at the end of the year on December 30th. At this point, it’ll be roughly due south at local sunset. Keep in mind, there’s also another ice giant worth hunting for in the adjacent constellation of Aquarius named Neptune.

So ignore those bad puns, and be sure to take out that 10” (scope, that is) and point it at Uranus!

Navigating the Cosmos by Quasar

A quasar resides in the hub of the nearby galaxy NGC 4438. Credit: NASA/ESA, Jeffrey Kenney (Yale University), Elizabeth Yale (Yale University)

50 million light-years away a quasar resides in the hub of galaxy NGC 4438, an incredibly bright source of light and radiation that’s the result of a supermassive black hole actively feeding on nearby gas and dust (and pretty much anything else that ventures too closely.) Shining with the energy of 1,000 Milky Ways, this quasar — and others like it — are the brightest objects in the visible Universe… so bright, in fact, that they are used as beacons for interplanetary navigation by various exploration spacecraft.

“I must go down to the seas again, to the lonely sea and the sky,
And all I ask is a tall ship and a star to steer her by.”
– John Masefield, “Sea Fever”

Deep-space missions require precise navigation, especially when approaching bodies such as Mars, Venus, or comets. It’s often necessary to pinpoint a spacecraft traveling 100 million km from Earth to within just 1 km. To achieve this level of accuracy, experts use quasars – the most luminous objects known in the Universe – as beacons in a technique known as Delta-Differential One-Way Ranging, or delta-DOR.

How delta-DOR works (ESA)
How delta-DOR works (ESA)

Delta-DOR uses two antennas in distant locations on Earth (such as Goldstone in California and Canberra in Australia) to simultaneously track a transmitting spacecraft in order to measure the time difference (delay) between signals arriving at the two stations.

Unfortunately the delay can be affected by several sources of error, such as the radio waves traveling through the troposphere, ionosphere, and solar plasma, as well as clock instabilities at the ground stations.

Delta-DOR corrects these errors by tracking a quasar that is located near the spacecraft for calibration — usually within ten degrees. The chosen quasar’s direction is already known extremely well through astronomical measurements, typically to closer than 50 billionths of a degree (one nanoradian, or 0.208533 milliarcsecond). The delay time of the quasar is subtracted from that of the spacecraft’s, providing the delta-DOR measurement and allowing for amazingly high-precision navigation across long distances.

“Quasar locations define a reference system. They enable engineers to improve the precision of the measurements taken by ground stations and improve the accuracy of the direction to the spacecraft to an order of a millionth of a degree.”

– Frank Budnik, ESA flight dynamics expert

So even though the quasar in NGC 4438 is located 50 million light-years from Earth, it can help engineers position a spacecraft located 100 million kilometers away to an accuracy of several hundred meters. Now that’s a star to steer her by!

Read more about Delta-DOR here and here.

Source: ESA Operations

SpaceX Says Falcon 9 Upper Stage Did Not Explode in Orbit (and it wasn’t a UFO, either)

The launch of SpaceX's Falcon 9 v.1.1 rocket from Vandenberg Air Force Base in California on September 29, 2013. Credit: SpaceX.

When the US Space Surveillance Network indicated they were tracking additional objects in orbit following Sunday’s maiden launch of SpaceX’s next generation rocket, speculation began among satellite trackers that the upper stage of the Falcon 9 v1.1. rocket may have exploded. But SpaceX issued a statement today that their data indicates no such explosion occurred, and that insulation may have come off the second stage, creating extra objects.

Meanwhile, SpaceX CEO Elon Musk confirmed via Twitter that reports of a “fuzzy” UFO over South Africa following the launch came from liquid oxygen released by the Falcon 9 rocket’s second stage.


In the September 29 launch from Vandenberg Air Force Base in California, SpaceX successfully launched and deployed the Canadian Space Agency’s CASSIOPE weather satellite (Cascade, Smallsat, and Ionospheric Polar Explorer) and six additional small satellites.

SpaceTrack was tracking 20 objects from the launch, but only fourteen should have been in orbit (CASSIOPE, 6 small sats, 4 spacers from the POPACS satellite trio, the second stage and two fairings) leaving ssix objects unaccounted for.

“Regarding the rumors you may have heard about the Falcon 9 second stage, in short, our data confirms there was no rupture of any kind on the second stage,” SpaceX spokeswoman Emily Shanklin wrote in an email on October 1.

SpaceX gave this account of what likely happened after launch:

Following separation of the satellites to their correct orbit, the Falcon 9 second stage underwent a controlled venting of propellants (fuel and pressure were released from the tank) and the stage was successfully safed. During this process, it is possible insulation came off the fuel dome on the second stage and is the source of what some observers incorrectly interpreted as a rupture in the second stage. This material would be in several pieces and be reflective in the Space Track radar. It is also possible the debris came from the student satellite separation mechanisms onboard.

The new, more powerful version of the Falcon 9 is powered by a cluster of nine of the new Merlin 1D engines that are about 50% more powerful compared to the standard Merlin 1C engines and can therefore boost a much heavier cargo load to the ISS and beyond. The Falcon 9 v.1.1 is taller than a standard Falcon 9: about 22 stories high vs. 13.

Musk told reporters at a post-launch news conference that they attempted to reignite the upper stage after payload separation for demonstrating the capability of putting satellites into a geostationary transfer orbit. However, the reignition sequence was aborted after a problem was detected.

Several images and videos were posted online of a UFO seen over South Africa, Madagascar, Botswana, and Malawi. But it was quickly determined to be a cloud of rocket propellant surrounding the spent Falcon 9 upper stage.

SpaceX said they will continue to review their data to help identify the source of the extra debris.

55 Years of NASA

55 Years of the National Aeronautics and Space Administration. Credit: NASA.

Today is NASA’s 55th birthday. Unfortunately, the celebration is muted due to the government shutdown, forcing much of NASA to shut down as well for the time being (see our overview of what’s still running at NASA and what’s not).

Before having to close the door (temporarily) today, NASA put together this nice graphic of the highlights of their accomplishments of the past 55 years, as well as what the hopes and plans are for the future.

The National Aeronautics and Space Administration began operating on October 1, 1958, managing the US’s burgeoning space exploration program. NASA replaced the National Advisory Committee for Aeronautics (NACA) agency, which began in 1915 to undertake and promote aeronautical research.

Now, NASA is in the midst of expanding commercial access to the International Space Station with the rendezvous of Orbital Science’s Cygnus capsule this week. While the ISS is still operating, and when full operations resume throughout NASA, they’ll continue work on exploring space, monitoring Earth, unlocking mysteries of our solar system and peering back into the beginnings of the Universe.

Our advice to you? If you are a US citizen, write your Congress-people and tell them how important you feel NASA is to the future of the nation and the world. And while you’re at it, tell them to get to work and do the job they were elected to do. Find out who represents you in the US Congress here.

This Very Old Cosmic Light Has A Bend To It

Artist's impression of how huge cosmic structures deflect photons in the cosmic microwave background (CMB). Credit: ESA and the Planck Collaboration

Leftover radiation from the Big Bang — that expansion that kick-started the universe — can be bent by huge cosmic structures, just like other light that we see in the universe. While the finding seems esoteric at first glance, scientists say the discovery could pave the way for finding a similar kind of signal that indicate the presence of gravitational waves in the moments after the universe was born.

That light is called the cosmic microwave background and is the radiation that was visible when the universe became transparent to radiation, 380,000 years after the Big Bang. A tiny bit of the CMB is polarized. There are two types of polarized light in the CMB: E-modes (first detected in 2002) and B-modes (which were just detected using a telescope in Antarctica and ESA’s Herschel space observatory.

“[B-modes] can arise in two ways,” the European Space Agency wrote in a press release.

“The first involves adding a twist to the light as it crosses the Universe and is deflected by galaxies and dark matter – a phenomenon known as gravitational lensing. The second has its roots buried deep in the mechanics of a very rapid phase of enormous expansion of the Universe, which cosmologists believe happened just a tiny fraction of a second after the Big Bang – ‘inflation’.”

More results are on the way from ESA’s Planck telescope in 2014, at which point scientists hope to see this B-mode of the second type. For now, check out the full study in Physical Review Letters. There is also a preprint version available on Arxiv.

Sources: ESA and ESA Herschel

What Does The Government Shutdown Mean For NASA?

The MAVEN missions ‘Going to Mars’ campaign invites the public to submit names and poems which will be included on a special DVD. The DVD will be adhered to the MAVEN spacecraft and launched to Mars on Nov. 18, 2013. Credit: NASA/GSFC

A forthcoming NASA launch to Mars could be in danger of losing its launch window should a shutdown in the United States federal government that began today (Oct. 1) continue for a while. That’s just one of the ways in which NASA is affected amid a lapse of funding that is affecting all government agencies and an untold number of government contractors.

Around 97% of NASA’s 18,000 employees are off the job. Twitter, Facebook, Google Plus and other social media accounts are going dark. NASA’s website is being pulled offline. NASA Television has also ceased broadcasting.

Beyond the agency’s public face, activities ranging from certain commercial crew payouts, to conference attendance, to scientific work will cease. Awards and scholarship approvals will be delayed.

“NASA will shut down almost entirely,” said President Barack Obama in a speech late Monday (Sept. 30).

NASA_twitter1NASA_twitter2

In addition to the agency’s public relations activities, NASA is planning to launch the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft to Mars in November to examine the Red Planet’s atmosphere. There are all sorts of questions vexing scientists concerning that planet, with one of the most prominent ones being why the atmosphere thinned over the years.

Media reports indicate that if the shutdown is lengthy, MAVEN could miss the launch window and have to try again in 2016.

“A shutdown could delay the pre-launch processing currently under way with a possible impact to the scheduled Nov. 18 launch date,” Dwayne Brown, a NASA senior public affairs officer at NASA, told The Planetary Society in a story published yesterday (Sept. 30). The launch window extends for several weeks beyond that time, however.

The 3% of NASA employees who are deemed essential will work without pay until the situation is resolved. These are some of the things that will continue:

The International Space Station.  Credit: NASA
The International Space Station. Credit: NASA
  • International Space Station monitoring will be maintained, but with the bare minimum of ground crew. (NASA will cease regular updates of the astronauts’ activities during the furlough, although we presume if something urgent happened there would be an update.)
  • Robotic missions that are already in operation — think the Cassini spacecraft circling Saturn, or the Lunar Atmosphere and Dust Environment Explorer (LADEE) winging its way to the moon — will have small crews making sure that they are functioning properly. No scientific analysis will be conducted, though.
  • Certain other programs will continue if a shutdown would be detrimental to their performance. Space News reports that the much-delayed James Webb Space Telescope will be among them, as some of its instruments are undergoing cryogenic vacuum testing at the Goddard Space Flight Center.
  • Update, 1:09 p.m. EDT: Several missions run out of the Jet Propulsion Laboratory and Applied Physics Laboratory are running as usual for at least the next week because these facilities are running under contracted money from NASA and still have funds in the bank. According to the Planetary Society’s Emily Lakdawalla: “At JPL, that includes: Curiosity; Opportunity; Odyssey; Mars Reconnaissance Orbiter; Cassini; Dawn; Juno; Spitzer; the Voyagers; and WISE, among many others. At APL, that includes MESSENGER and New Horizons. It also includes the Deep Space Network.”
  • Additional Update, 2:09 p.m. EDT: The HiRISE twitter account just replied to inquiries from several space journalists that they will be “open for business” as usual, which is great news since the Mars Reconnaissance Orbiter made an audacious attempt to take images of Comet ISON during the comet’s closest approach to Mars today. We’ll provide any news and updates on images as they become available, but the HiRISE team said getting the images back to Earth and processing them may take a day or two.
  • Many observers noted that NASA is marking its 55th anniversary today by shutting down its activities. There’s no word yet on when the deadlock in Congress will be resolved. The last two shutdowns in 1995 and 1996 (which began in the middle of the STS-74 shuttle mission to Mir) lasted several weeks.

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    SEDS

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    First Cloudy Alien Planet Spotted From Earth

    Cloud map of Kepler-7b (left) in comparison to Jupiter (right). Credit: NASA/JPL-Caltech/MIT

    Call it cloudy with a low chance of meatballs. The alien world Kepler-7b — a very reflective world in big telescopes — has clouds in its upper atmosphere. And scientists have actually been able to map those out, despite the planet’s great distance from Earth (at least 1,000 light-years away.)

    It’s the first time scientists have been able to map out clouds on a world outside of the solar system. If we can see clouds, then we can begin to think about what a planet’s climate will be, making this an important milestone in understanding the conditions on other worlds.

    “Kepler-7b reflects much more light than most giant planets we’ve found, which we attribute to clouds in the upper atmosphere,” stated Thomas Barclay, Kepler scientist at NASA’s Ames Research Center. “Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time — it has a remarkably stable climate.”

    Illustration of the Kepler spacecraft (NASA/Kepler mission/Wendy Stenzel)
    Illustration of the Kepler spacecraft (NASA/Kepler mission/Wendy Stenzel)

    Here’s how scientists got it done:

    • Preliminary observations with the Kepler space telescope –which was designed to hunt planets until a second reaction wheel failed earlier this year — found “moon-like phases” on Kepler-7b. These showed a bright spot on the western  hemisphere.
    • NASA’s Spitzer Space Telescope measured Kepler-7b’s temperature using infrared light, calculating it at between 1,500 and 1,800 degrees Fahrenheit (815 and 982 degrees Celsius.)
    • Something was clearly going on, as the planet is extremely close to its star; only 0.06 Earth-sun distances away. The temperature was too cool. They figured out that the light was reflected off cloud tops on the planet’s west side.

    Another cool fact — Kepler-7b, like Saturn, would float if it was put in a big enough tub of water!

    You can read more details in the technical paper online here. The study, which was led by the Massachusetts Institute of Technology, has been accepted to the Astrophysical Journal, but not published yet.

    Source: NASA

    Carnival of Space #321

    Carnival of Space. Image by Jason Major.
    Carnival of Space. Image by Jason Major.

    This week’s Carnival of Space is hosted by Stefan Lamoureux at his Links Through Space blog.

    Click here to read Carnival of Space #321.

    And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

    How Long Will Life Survive on Earth?

    A powerful X-class solar flare erupting on the sun on July 6, 2012 photographed by the Solar Dynamics Observers. Credit: NASA

    Life has existed on Earth for billions of years, appearing shortly after the planet had cooled and liquid water became available.

    From the first bacteria to the amazingly complex animals we see today, life has colonized every corner of our planet.

    As you know, our Sun has a limited lifespan.

    Over the next 5 billion years, it will burn the last of its hydrogen, bloat up as a red giant and consume Mercury and Venus.

    This would be totally disastrous for local flora and fauna, but all life on the surface of the Earth will already be long gone.

    In fact, we have less than a billion years to enjoy the surface of our planet before it becomes inhospitable.

    Because our Sun… is heating up.

    You can’t feel it over the course of a human lifetime, but over hundreds of millions of years, the amount of radiation pouring out of the Sun will grow.

    This will heat the surface of our planet to the point that the oceans boil.

    At the core of the Sun, the high temperatures and pressures convert hydrogen into helium. For every tonne of material the Sun converts, it shrinks a bit making the Sun denser, and a little hotter.

    Over the course of the next billion years or so, the amount of energy the Earth receives from the Sun will increase by about 10%. Which doesn’t sound like much, but it means a greenhouse effect of epic proportions.

    A TerraSAR-X stripmap image from 23 April 2009. The larger icebergs are bright, while smaller icebergs are capsized and appear as dark blocks. The inset shows two superimposed Envisat ASAR images from 24 and 27 April. The region outlined in red indicates the area of the TerraSAR-X image.   Credits: DLR, ESA (Annotations by A. Humbert, Münster University
    A TerraSAR-X stripmap image of icebergs.
    Whatever is left of the ice caps will melt, and the water itself will boil away, leaving the planet dry and parched. Water vapor is a powerful greenhouse gas, this will drive the temperatures even hotter.

    Plate tectonics will shut down, and all the carbon will be stripped from the atmosphere.

    It’ll be bad.

    As temperatures rise, complex lifeforms will find life on Earth less hospitable. It will seem as if evolution is running in reverse, as plants and animals die off, leaving the invertebrates and eventually just microbial life.

    This rise in temperature will be the end of life on the surface of Earth as we know it.

    Still, there are reserves of water deep underground which will continue to protect microbial life for billions of years.

    Perhaps they’ll experience that final baking when the Sun does reach the end of its life.

    Even a few hundred million years is an incomprehensible amount of time compared to the age of our civilization.

    If humanity does survive well into the future, is there anything we could do about this problem?

    As the Sun heats up, making Earth inhospitable, it heats up the rest of the Solar System too. Frozen worlds in the Solar System will melt, becoming more habitable.

    Encaladus, a moon of Saturn, as shown in this Voyager 1 image. Credit: NASA
    Encaladus, a moon of Saturn, as shown in this Voyager 1 image. Credit: NASA
    It’s possible that future civilizations could relocate to the asteroid belt, or the moons of Saturn. We could try something even more radical: move the Earth.

    By carefully steering asteroids so they barely miss us, an advanced civilization could distort the Earth’s orbit, relocating our planet further from the Sun.

    As the Sun heats up, our planet would be continuously repositioned so the surface temperature stays roughly the same. Of course, this would be tricky business. Make the wrong move, and you’re facing the frigid cold of the outer Solar System.

    So there’s no need to panic. Life here has a few hundred million years left; a billion, tops. But if we want to continue on for billions of years, we’ll want to add solar heating to our growing list of big problems.

    Giveaway: Sky Live for iOS5 and Up

    A new app called “Sky Live” was just released  from Vito Technologies and it will save you countless planning hours in your stargazing agendas. Vito Technologies, through a super-secret process, has discovered a way to give users a sky watching forecast anywhere in the world for up to 7 days in advance.

    Were you planning a camping trip to watch the Perseid Meteor Shower? Is Venus going to be in the perfect spot in the sky to pull out your telescope and have a sky watching party? Sky watching is heavily dependant upon weather conditions and all that careful party planning is out the window when a bank of clouds settles in.

    Universe Today and Vito Technologies is giving away 10 free copies of this app. How do you enter your name for this “appy” goodness?

    In order to be entered into the giveaway drawing, just put your email address into the box at the bottom of this post (where it says “Enter the Giveaway”) before Monday, October 7, 2013. We’ll send you a confirmation email, so you’ll need to click that to be entered into the drawing.

    More info on this app from the Publisher:

    What it does: The main screen gives you one number: let’s say 78%.

    Same as Fahrenheit degrees in weather, this percentage gives you at-a-glance info on how good tonight is for stargazing. The number is calculated with a special formula that takes into account things like is there anything interesting in the sky tonight, how cloudy, how bright is the Moon, etc.

    Why it is different:

    The formula for our Stargazing Index is superbly original and highly confidential. Combined with stunning space images, we hope this will be the most beautiful and accurate stargazing forecast on the AppStore.

    Highlights:

    – New app from the developers of Apple Design Award winning stargazing app with over 7 mln users

    – Designed specifically for iOS7 (but will work on everything starting with iOS 5): blur and parallax, stunning graphics

    – Detailed info on stargazing conditions for any location in the world for seven days ahead

    vito2

    – Moon phases

    – Rise, set, culmination/azimuth for the most important objects: the Sun, the Moon, Mars, Venus, Jupiter, Saturn, and the International Space Station

    – Cloudiness

    – Weather forecast

    – Light pollution

    – The International Space Station position over the map

    – ISS crew data