This colorized composite shows more than half of Earth’s disk over the coast of Argentina and the South Atlantic Ocean as the Juno probe slingshotted by on Oct. 9, 2013 for a gravity assisted acceleration to Jupiter. The mosaic was assembled from raw images taken by the Junocam imager. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo
Um, something in my eye. This wonderful video details a what took place when the Jupiter-bound Juno spacecraft swung past Earth on Oct. 9, 2013 for a gravity assist, and amateur radio operators around the world sent a Morse Code saying “HI” to the spacecraft.
“We wanted to know, if this were an interplanetary spacecraft, could they we tell there was intelligent life on Earth?” said Bill Kurth, co-investigator for the Juno Waves Investigation from the University of Iowa.
Watch the video to find out if it worked.
“We obviously haven’t heard anything like this from any other planet,” said Scott Bolton, Juno principal investigator, speaking during a press briefing from the American Geophysical Union conference today in San Fransisco.
With remote-sensing satellites, scientists have found the coldest places on Earth, just off a ridge in the East Antarctic Plateau. The coldest of the cold temperatures dropped to minus 135.8 F (minus 93.2 C) -- several degrees colder than the previous record.
Image Credit: Ted Scambos, National Snow and Ice Data Center.
What is the coldest place on Earth? Scientists say it’s a place so cold that ordinary mercury or alcohol thermometers won’t work there. If you were there, every breath would be painful, your clothing would crackle every time you moved, and if you threw hot water into the air, it would fall to the ground as tiny shards of ice. At this place, the new record of minus 136 F (minus 93.2 C) was set on Aug. 10, 2010. Researchers analyzed data from several satellite instruments and found the coldest place on Earth in the past 32 years is … a high ridge in Antarctica between Dome Argus and Dome Fuji, two summits on the ice sheet known as the East Antarctic Plateau. Temperatures in several hollows were found to dip to the new record.
“We had a suspicion this Antarctic ridge was likely to be extremely cold,” said Ted Scambos, from the National Snow and Ice Data Center in Boulder, Colorado. “With the launch of Landsat 8, we finally had a sensor capable of really investigating this area in more detail.”
This beats out the previous low of minus 128.6 F (minus 89.2 C), set in 1983 at the Russian Vostok Research Station in East Antarctica. The coldest permanently inhabited place on Earth is northeastern Siberia, where temperatures in the towns of Verkhoyansk and Oimekon dropped to a bone-chilling 90 degrees below zero Fahrenheit (minus 67.8 C) in 1892 and 1933, respectively.
Scambos and his team made the discovery while analyzing the most detailed global surface temperature maps to date, developed with data from remote sensing satellites. The new findings were reported at the American Geophysical Union meeting in San Francisco.
The pursuit to find the coldest place on Earth started when the researchers were studying large snow dunes, sculpted and polished by the wind, on the East Antarctic Plateau. When the scientists looked closer, they noticed cracks in the snow surface between the dunes, possibly created when wintertime temperatures got so low the top snow layer shrunk. This led scientists to wonder what the temperature range was, and prompted them to hunt for the coldest places using data from two types of satellite sensors.
They used data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites and the Advanced Very High Resolution Radiometer (AVHRR) on several National Oceanic and Atmospheric Administration satellites. These sensitive instruments can pick up thermal radiation emitted from Earth’s surface, even in areas lacking much heat.
Using these sensors to scan the East Antarctic Plateau, Scambos detected extremely cold temperatures on a 620-mile stretch of the ridge at high elevations between Argus and Fuji, and even colder temperatures lower elevations in pockets off the ridge. Then, with the higher resolution of the Thermal Infrared Sensor (TIRS) aboard Landsat 8, the research team pinpointed the record-setting pockets.
The team compared the sites to topographic maps to explore how it gets so cold. Already cold temperatures fall rapidly when the sky clears. If clear skies persist for a few days, the ground chills as it radiates its remaining heat into space. This creates a layer of super-chilled air above the surface of the snow and ice. This layer of air is denser than the relatively warmer air above it, which causes it to slide down the shallow slope of domes on the Antarctic plateau. As it flows into the pockets, it can be trapped, and the cooling continues.
“By causing the air to be stationary for extended periods, while continuing to radiate more heat away into space, you get the absolute lowest temperatures we’re able to find,” Scambos said. “We suspected that we would be looking for one magical site that got extremely cold, but what we found was a large strip of Antarctica at high altitude that regularly reached these record low temperatures.”
This article was originally published on Aug 10, 2012. We’ve updated it and added this cool new video!
Sending spacecraft to Mars is all about precision. It’s about blasting off from Earth with a controlled explosion, launching a robot into space in the direction of the Red Planet, navigating the intervening distance between our two planets, and landing with incredible precision.
This intricate and complicated maneuver means knowing the exact distance from Earth to Mars. Since Mars and Earth both orbit the Sun – but at different distance, with different eccentricities, and with different orbital velocities – the distance between then is constantly changing
The first person to ever calculate the distance to Mars was the astronomer Giovanni Cassini, famous for his observations of Saturn. Giovanni made observations of Mars in 1672 from Paris, while his colleague, Jean Richer made the same observation from Cayenne, French Guiana. They used the parallax method to calculate the distance to Mars with surprising accuracy.
Every two years, the Earth passes Mars as they orbit around the Sun, which causes it to appear like it is slowing down and moving in reverse in the sky (aka. “retrograde motion”). Credit: Tunç Tezel
However, astronomers now calculate the distance to objects in the Solar System using the speed of light. They measure the time it takes for signals to reach spacecraft orbiting other planets. They can bounce powerful radar off planets and measure the time it takes for signals to return. This allows them to measure the distance to planets, like Mars, with incredible accuracy.
Distance Between Earth and Mars:
So, how far away is Mars? The answer to that question changes from moment to moment because Earth and Mars are orbiting the Sun. It also requires a little explanation about the orbital mechanics of each. Both Earth and Mars are following elliptical orbits around the Sun, like two cars travelling at different speeds on two different racetracks.
Sometimes the planets are close together, and other times they’re on opposite sides of the Sun. And although they get close and far apart, those points depend on where the planets are on their particular orbits. So, the Earth Mars distance is changing from minute to minute.
The planets don’t follow circular orbits around the Sun, they’re actually traveling in ellipses. Sometimes they’re at the closest point to the Sun (called perihelion), and other times they’re at the furthest point from the Sun (known as aphelion).
Mars axial tilt and eccentricity as it orbits around the Sun. Credit and copyright: Encyclopedia Britannica
To get the closest point between Earth and Mars, you need to imagine a situation where Earth and Mars are located on the same side of the Sun. Furthermore, you want a situation where Earth is at aphelion, at its most distant point from the Sun, and Mars is at perihelion, the closest point to the Sun.
Earth and Mars Opposition:
When Earth and Mars reach their closest point, this is known as opposition. It’s the time that Mars appears as a bright red star of the sky; one of the brightest objects, rivaling the brightness of Venus or Jupiter. There’s no question Mars is bright and close, you can see it with your own eyes. And theoretically at this point, Mars and Earth will be only 54.6 million kilometers from each other.
But here’s the thing, this is just theoretical, since the two planets haven’t been this close to one another in recorded history. The last known closest approach was back in 2003, when Earth and Mars were only 56 million km (or 33.9 million miles) apart. And this was the closest they’d been in 50,000 years.
Opposition occurs when Mars and Earth line up on the same side of the Sun. The two planets are closest together at that time. Credit: Bob King
Here’s a list of Mars Oppositions from 2007-2020 (source)
Dec. 24, 2007 – 88.2 million km (54.8 million miles)
Jan. 29, 2010 – 99.3 million km (61.7 million miles)
Mar. 03, 2012 – 100.7 million km (62.6 million miles)
Apr. 08, 2014 – 92.4 million km (57.4 million miles)
May. 22, 2016 – 75.3 million km (46.8 million miles)
Jul. 27. 2018 – 57.6 million km (35.8 million miles)
Oct. 13, 2020 – 62.1 million km (38.6 million miles)
2018 should be a very good year, with a Mars looking particularly bright and red in the sky.
Earth and Mars Conjunction:
On the opposite end of the scale, Mars and Earth can be 401 million km apart (249 million miles) when they are in opposition and both are at aphelion. The average distance between the two is 225 million km. When Mars and Earth are at their closest, you have your launch window.
Since 1995, Mars has been at such an “opposition” with the Sun seven times. A color composite from each of the seven Hubble opposition observations has been assembled in this mosaic to showcase the beauty and splendor that is The Red Planet. Credit: NASA/ESA
Mars and Earth reach this closest point to one another approximately every two years. And this is the perfect time to launch a mission to the Red Planet. If you look back at the history of launches to Mars, you’ll notice they tend to launch about every two years.
Here’s an example of recent Missions to Mars, and the years they launched:
MER-A Spirit – 2003
MER-B Opportunity – 2003
Mars Reconnaissance Orbiter – 2005
Phoenix – 2007
Fobos-Grunt – 2011
MSL Curiosity – 2011
See the trend? Every two years. They’re launching spacecraft when Earth and Mars reach their closest point.
Spacecraft don’t launch directly at Mars; that would use up too much fuel. Instead, spacecraft launch towards the point that Mars is going to be in the future. They start at Earth’s orbit, and then raise their orbit until they intersect the orbit of Mars; right when Mars is at that point. The spacecraft can then land on Mars or go into orbit around it. This journey takes about 250 days.
Communicating with Mars:
With these incredible distances between Earth and Mars, scientists can’t communicate with their spacecraft in real time. Instead, they need to wait for the amount of time it takes for transmissions to travel from Earth to Mars and back again.
Artist’s impression of the Spirit Rover. One of two rovers that were part of MER program, the other was Opportunity, that began communicating back information that have helped NASA scientists characterize the Martian environment and geological history. NASA/JPL-Caltech
When Earth and Mars are at their theoretically closest point of 54.6 million km, it would take a signal from Earth about 3 minutes to make the journey, and then another 3 minutes for the signals to get back to Earth. But when they’re at their most distant point, it takes more like 21 minutes to send a signal to Mars, and then another 21 minutes to receive a return message.
This is why the spacecraft sent to Mars are highly autonomous. They have computer systems on board that allow them to study their environment and avoid dangerous obstacles completely automatically, without human intervention.
The distance from Earth to Mars is the main reason that there has never been a manned flight to the Red Planet. Scientists around the world are working on ways to shorten the trip with the goal of sending a human into Martian orbit within the next decade.
For more information, this website lists every Mars opposition time, from recent past all the way in the far future. You can also use NASA’s Solar System Simulator to see the current position of any object in the Solar System.
It’s actually remarkably beautiful, and well worth two minutes of your time.*
Assembled from actual photographs taken by astronauts aboard the Space Station, many of them by Don Pettit during Expedition 31 (Don took a lot of photos) this timelapse “The World Outside My Window” by David Peterson ramps up the artistic value by featuring super-duper high definition, smoothed frame transitions and a musical score by “Two Steps From Hell.” (Don’t worry, that sounds scarier than it is.) Even if you’ve seen some of these clips before, they’re worth another go.
After all, there’s no good reason not to be reminded of how beautiful our planet is from space. Enjoy!
*It’s actually two minutes and twenty-eight seconds but I don’t think you’ll mind.
Image taken by astronauts on the International Space Station showing an oblique view of an eruption plume emanating from the Kliuchevskoi volcano on Russia’s Kamchatka Peninsula. Credit: NASA.
We’ve seen some great views from space of erupting volcanoes, like Pavlov, Shiveluch, and Nabro. While most of the views from space look straight down in a in a nadir view, this photo was taken from the International Space Station with an oblique or sideways viewing angle. This provides a three-dimensional-type view, similar to what might be seen from an airplane instead of a flattened view that looks straight down. This image was taken by an astronaut when the ISS was located over a ground position more than 1,500 kilometers (900 miles) to the southwest of the Kamchatka Peninsula in the far eastern part of Russia. The Kliuchevskoi volcano is just one of 160 volcanoes in this region, with 29 of the 160 being active.
NASA says the plume—likely a combination of steam, volcanic gases, and ash—stretched to the east-southeast due to prevailing winds. The dark region to the north-northwest is likely a product of shadows and of ash settling out. Several other volcanoes are visible in the image, including Ushkovsky, Tolbachik, Zimina, and Udina. To the south-southwest of Kliuchevskoi lies Bezymianny Volcano, which appears to be emitting a small steam plume (at image center).
These volcanic peaks are an eye-catching landmark from orbit. Here’s an image of the same region taken by astronaut Chris Hadfield earlier this year:
Volcanoes of Kamchatka, Russia at dawn, as seen from the International Space Station. Credit: NASA/CSA/Chris Hadfield
Comet ISON entered the STEREO scene with Encke on Nov. 21 (Credit: Karl Battams/NASA/STEREO/CIOC)
As comets ISON and Encke continue toward their respective rendezvous with the Sun, they have now both been captured on camera by NASA’s solar-observing STEREO spacecraft. The image above, taken on Nov. 21 (UT) with STEREO-A’s high-resolution HI-1 camera, shows ISON as it enters the field of view from the left. Encke is at center, while the planets Mercury and Earth (labeled) are bright enough to cause vertical disruptions in the imaging sensors. (The Sun is off frame to the right.)
As cool as this image is, it gets even better: there’s a video version. Check it out below:
Animation of STEREO-A images acquired on Nov. 20-21 (Karl Battams/NASA/STEREO/CIOC)
The dark “clouds” coming from the right are density enhancements in the solar wind, causing all the ripples in comet Encke’s tail. (Source)
The position of NASA’s STEREO spacecraft relative to Earth and the Sun on Nov. 22
It’s fascinating to watch how the solar wind shapes and affects the tail of comet Encke… as ISON moves further into view, I’m sure we’ll see similar disruptions in its tail as well. (And look what STEREO-A saw happen to Encke’s tail back in 2007!)
Encke reached the perihelion of its 3.3-year-long orbit on Nov. 21; newcomer ISON will arrive at its on Nov. 28. While it seems to be holding together quite well in these STEREO images, what happens when it comes within 730,000 miles of the Sun next week is still anybody’s guess.
An erupting undersea volcano forms a new island off the coast of Nishinoshima, a small unihabited island in the southern Ogasawara chain of islands. The image was taken on November 21, 2013 by the Japanese Coast Guard.
A volcanic eruption is creating a tiny new island off the coast of Japan. The Japanese Coast Guard snapped images and video of the eruption taking place, showing the new island being formed. Footage showed heavy smoke, ash and rocks spewing from the volcanic crater. As of this writing, experts say the small island is about 200 meters (660 feet) in diameter. It is located just off the coast of Nishinoshima, a small, uninhabited island in the Ogasawara chain, also known as the Bonin Islands, about about 620 miles (1,000 km) south of Tokyo.
See a video and additional images below.
Only time will tell if the island will remain or if the ocean waters will reclaim it. According to Yahoo News, Japan’s chief government spokesman said they would welcome any new territory.
“This has happened before and in some cases the islands disappeared,” Yoshihide Suga said when asked if the government was planning on naming the new island. “If it becomes a full-fledged island, we would be happy to have more territory.”
An erupting undersea volcano forms a new island, shown by its nearest neighbor, Nishinoshima, a small unihabited island in the southern Ogasawara chain of islands. The image was taken on November 21, 2013 by the Japanese Coast Guard.This screenshot of Google Maps shows all the volcanoes in the The Japan, Taiwan, Marianas Region. Via Google Maps and the Smithsonian volcano website.
According to the Smithsonian Global Volcanism Program website, the Japan, Taiwan, Marianas Region is a very active region in the Pacific Ring of Fire and most volcanoes in this region “result from subduction of westward-moving oceanic crust under the Asian Plate. In the Izu-Mariana chain, however, the crust to the west is also oceanic, forming more basaltic island arcs (but with volcanoes that are far more explosive than oceanic hotspot volcanoes).”
A view of rivers in Montana, USA, from the ISS. Credit: ESA/Luca Parmitano.
A Canadian camera system aiming to provide near-realtime video views of Earth is readying for a launch from Kazakhstan.
If all goes well, the UrtheCast dual camera system will blast off in a Progress supply ship on Nov. 25, 2013.
This will be the world’s first ever high definition, live-streaming video platform of planet Earth from the International Space Station.
“Imagine you have a nearly live Google Earth, but it isn’t four year old data – you have data that is being refreshed all the time, with videos coming down over interesting areas where interesting events are going on, showing you what is changing, what is going on,” said George Tyc, the Chief Technology Officer at UrtheCast, in an interview with Universe Today earlier this year. “What we really hope to pull off is to change the paradigm, get the everyday person interacting and seeing the data coming down from space to see the Earth and how it is evolving over time in a way that isn’t available right now.”
Last week at the Canadian Space Society Summit, UrtheCast co-founder Wade Larson explained the camera setup will take place in phases, with Phase 1 of the project having two cameras facing the ground, with one having a fixed gaze and the other one featuring maneuverability to points of interest. These should be installed on the station sometime in December 2013, Larson said, with data coming in the first quarter of 2014.
The company’s aim is to make Earth video data more accessible to individuals and schoolchildren, who would log in on UrtheCast’s website, as well as the traditional customers of government and private companies. Additionally, a recent partnership agreement with the UN will see them offer real-time information on dynamic situations such as floods and mass movements of people during humanitarian disasters. They will also be integrating the data with live social media feeds as well as opening up their API for app developers.
The UK covered in snow, as seen on Dec. 8, 2010. Credit: NASA’s Aqua satellite.
Current sponsors on the project from UrtheCast (pronunced “Earthcast”) include Roscosmos, MacDonald, Dettwiler and Associates, the Discovery Channel, Energia, Unosat and RAL Space, Larson added.
The UrtheCast team is working in an exclusive relationship with the Russian Aerospace giant RSC Energia (NASA is not involved at all), and cosmonauts on board the ISS will install the cameras. The video data of the Earth will be down-linked to ground stations around the planet and then displayed in near real time on the UrtheCast web platform.
“We had to meet quite a strict set of requirements that the cameras are safe for cosmonauts and astronauts,” Tyc said, “as there can’t be any toxic substances because they will be inside the ISS before they are installed.”
Tyc added that it will take two spacewalks to do the full installation. The cameras are expected to last at least five years, and Tyc expects them to be up there even longer. “We’re looking at putting additional cameras up there for a second generation, and we expect to be up there for the life of the station, really,” he said.
Tyc said he thinks the social media aspect of UrtheCast will be a big part of the entire experience.
“For example, in a natural disaster or big event we’ll also incorporate videos from the ground of things going on, to experience an event in a far different way than you can now,” he said. “And it’s not being filtered through a media agency — it is what it is – and people can draw their own conclusions and add their own voice.”
Tyc said that if the concept takes off, they think this will be a shift in how people can interact with others around the world. “It could be a feeling of the Overview effect – people who go to space are have a completely changed perspective – we’re trying to bring a little bit of that to the ground,” he said.
The team said the name UrtheCast is a bit of a double entendre, as it is pronounced like “EarthCast” but also looks like “You Are the Cast” since it will be live views of planet Earth.
The "pale blue dot" of Earth as seen from Cassini on July 19, 2013.
This summer, for the first time ever, the world was informed that its picture was going to be taken from nearly a billion miles away as the Cassini spacecraft captured images of Saturn in eclipse on July 19. On that day we were asked to take a moment and smile and wave at Saturn, from wherever we were, because the faint light from our planet would be captured by Cassini’s camera, shielded by Saturn from the harsh glare of the Sun.
A few preliminary images were released just a few days later showing the “pale blue dot” of Earth nestled within the glowing bands of Saturn’s rings. It was an amazing perspective of our planet, and we were promised that the full mosaic of Cassini images was being worked on and would be revealed in the fall.
Well, it’s fall, and here it is:
The full mosaic from the Cassini imaging team of Saturn on July 19, 2013… the “Day the Earth Smiled”
“After much work, the mosaic that marks that moment the inhabitants of Earth looked up and smiled at the sheer joy of being alive is finally here. In its combination of beauty and meaning, it is perhaps the most unusual image ever taken in the history of the space program.”
In this panorama of the Saturnian system, a view spanning 404,880 miles (651,591 km), we see the planet silhouetted against the light from the Sun. It’s a unique perspective that highlights the icy, reflective particles that make up its majestic rings and also allows our own planet to be seen, over 900 million miles distant. And it’s not just Earth that was captured, but the Moon, Venus, and Mars were caught in the shot too.
According to the description on the CICLOPS page, “Earth’s twin, Venus, appears as a bright white dot in the upper left quadrant of the mosaic… between the G and E rings. Mars also appears as a faint red dot embedded in the outer edge of the E ring, above and to the left of Venus.”
This was no simple point-and-click. Over 320 images were captured by Cassini on July 19 over a period of four hours, and this mosaic was assembled from 141 of those images. Because the spacecraft, Saturn, and its moons were all in constant motion during that time, affecting not only positions but also levels of illumination, imaging specialists had to adjust for that to create the single image you see above. So while all elements may not be precisely where they were at the same moment in time, the final result is no less stunning.
“This version was processed for balance and beauty,” it says in the description. (And I’ve no argument with that.)
See below for an annotated version showing the position of all visible objects, and read the full article on the CICLOPS page for an in-depth description of this gorgeous and historic image.
2013 Saturn mosaic, annotated version.
“I hope long into the future, when people look again at this image, they will recall the moment when, as crazy as it might have seemed, they were there, they were aware, and they smiled.”
All images credit NASA/JPL-Caltech/Space Science Institute
UPDATE 11/13: CICLOPS Director Carolyn Porco describes how this image was acquired and assembled in this interview video from the World Science Festival:
This article was originally written in 2010, but we’ve now updated it and added this spiffy new video.
As you probably know, the Earth is rotating on its axis. This gives us day and night. Of course it’s impossible, but what would happen if the Earth stopped spinning? Remember, this isn’t possible, it can’t happen, so don’t worry.
Everything would be launched in a ballistic trajectory sideways
The first thing to think about is the momentum of everything on the surface of the Earth. You’re held down by gravity and you’re whizzing through space at a rotational velocity of 1,674.4 km/h (at the equator). You can’t feel it because of momentum. Just like how you can’t feel that you’re moving in a car going down the highway. But you feel the effects when you stop, or get into an accident. And so, if the Earth suddenly stopped spinning, everything on the surface of the Earth at the equator would suddenly be moving at more than 1,600 km/hour sideways. The escape velocity of Earth is about 40,000 km/hour, so that isn’t enough to fly off into space; but it would cause some horrible damage as everything flew in a ballistic trajectory sideways. Imagine the oceans sloshing sideways at 1,600 km/hour.
The rotational velocity of the Earth decreases as you head away from the equator, towards the poles. So as you got further away from the equator, your speed would decrease. If you were standing right on the north or south pole, you’d barely even feel it.
A day would last 365 days
The next problem is that day and night wouldn’t work the same any more. Right now the Earth is rotating on its axis, returning the Sun to the same position every 24 hours. But if the Earth stopped spinning, it would then take 365 days for the Sun to move through the sky and return to the same position. Half of the Earth would be baked for half a year, while the other hemisphere was in darkness. It would get very hot on the sunny side, and very cold in the shadowed side. You can imagine how that would be devastating to plants and animals. We get a hint of this at the poles, where you can experience weeks of permanent night and then weeks of permanent day. But imagine 6 months of night, followed by 6 months of day.
The Earth would become a perfect sphere
This might seem minor compared to the other catastrophes, but the Earth would become an almost perfect sphere. The Earth is currently rotating on its axis, completing one turn approximately every 24 hours. This rotational velocity causes the Earth to bulge out around its equator, turning our planet into an oblate spheroid (a flattened ball). Without this spin, gravity would be able to pull the Earth into a nice perfect sphere. This sounds interesting and probably harmless, but it’s actually a *big* problem. Because of the Earth’s bulge in the middle, the oceans are held out at the equator by 8 km. On perfect sphere Earth, the world’s oceans would redistribute, flooding many regions of the planet with an immense volume of water. We’d end up with a single continent around the middle of the planet, with oceans surrounding the north and south poles.
The Earth would no longer be tilted
The Earth’s tilt is defined by how the planet is rotating compared to the Sun. This axis of rotation defines the Earth’s seasons. But without any rotation, the concept doesn’t make sense any more. There’s still a north pole of the planet, where the radiation from the Sun is at its lowest angle, and an equator, where the light hits most directly. But there would no longer be seasons.
