The northeastern US and southeastern Canada, as seen from space on January 13, 2015. Image is from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. acquired top image on January 13, 2015.
Yes, its been a snowy, icy winter in parts of the US, Canada and Europe and these satellite images look about as miserable as it’s felt for some of us. And no, those aren’t icicles hanging off the coast of Maine and Nova Scotia; those are called ‘cloud streets,’ which are long parallel bands of cumulus clouds that form when cold air blows over warmer waters (like the ocean) and a warmer air layer (temperature inversion) rests over the top of both.
But don’t let the recent cold weather and snow fool you. The Earth as a whole continues to warm, and NASA and NOAA announced today that their analysis puts 2014 as Earth’s warmest year since 1880. 2014 was the 38th straight year with above average global annual temperatures, and December 2014 was the hottest December on record. Additionally, 6 of the 12 months last year set heat records. Even though you might feel cold right now, the last time there was a monthly average global temperatures that set a record for cold was in 1916.
OK, now back to the regularly scheduled feeling sorry for ourselves for the recent cold, snowy weather… see more satellite images below.
Winter storms brought snow and ice to a large portion of the U.S. Midwest and Northeast. NASA’s Aqua satellite acquired this image on January 10, 2015. Credit: NASA.Snow and ‘cloud streets’ over the Black Sea on January 8, 2015. Image is from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite. Credit: NASA.
Here’s a video from NASA about the latest findings on Earth’s changing climate:
Orion (at right), Sirius (bottom) and the pale wintertime Milky Way (center) are well-placed for viewing around 11 o'clock local time in late November. Credit: Bob King
Several nights ago the chill of interstellar space refrigerated the countryside as temperatures fell well below zero. That didn’t discourage the likes of Orion and his seasonal friends Gemini, Perseus and Auriga. They only seemed to grow brighter as the air grew sharper.
Wending between these familiar constellations like a river steaming in the cold was the Milky Way. The name has always been slightly confusing as it refers to both the milky band of starlight and the galaxy itself. Every single star you see at night belongs to our galaxy, a 100,000 light-year-wide flattened disk scintillating with over 400 billion suns.
Face-on (left) and edge-on views of the Milky Way. Our solar system lies in the flat plane of a barred spiral galaxy called the Milky Way. Looking through the plane, the stars pile up to form the Milky Way band. In summer, we face toward the richer, denser core; in winter we look out toward the edge. Credit: NASA with annotations by the author
Earth, Sun and planets huddle together within the mid-plane of the disk, so that when we look straight into it, the density of stars piles up over thousands of light years to form a thick band across the sky. Since most of the stars are very distant and therefore faint, they can’t be seen individually with the naked eye. They blend together to give the Milky Way a milky or hazy look.
During a snowfall, we can see individual flakes nearby but more distant ones increase in number and blend to make a uniform haze similar to what happens when we look across the flat disk of the Milky Way. Credit: Bob King
In a snowstorm, we easily distinguish individual snowflakes falling in front of our face, but looking into the distance, the flakes blend together to create a white, foggy haze. Replace the snowflakes with stars and you have the Milky Way – with a caveat. If we lived in the center of our galaxy, the sky would be milky with stars in all directions just like that snowstorm, but since the Sun occupies the flat plane, they only appear thick when our line of sight is aimed along the galaxy’s equator. Look above and below the disk and the stars quickly thin out as our gaze pierces through the galaxy’s plane and into intergalactic space.
In this view, the ground – Earth – has been removed from the picture and we can see all around us in space. Now we can see that the Milky Way band describes a full circle in the sky. The blue circle represents the galactic equator. The view shows the sky around midnight in early December. The Sun, at lower right, lies in the same direction as the galaxy’s center this month. Source: Stellarium
If you could float in space some distance from the brilliant ball of Earth, you’d see that the Milky Way band passes above, around and below you like a giant hula-hoop. Back on the ground, we can only see about two-thirds of the band over the course of a year. The other third is below the horizon and visible only from the opposite hemisphere, providing yet another good reason to make that trip to Tahiti or Ayers Rock in Australia.
Few know the winter version of the Milky Way that stands above the southeastern horizon around 10:30-11 p.m. local time on moonless nights in early December. No surprise, given it hardly compares to the brightness of the summertime version. This has much to do with where the Sun is located inside the galaxy, some 30,000 light years away from the center or more than halfway to the edge.
Opposite the galaxy’s center lies the anticenter, located near El Nath in the northern horn of Taurus above the constellation Orion. Source: Stellarium
On late fall and winter nights, our planet faces the galaxy’s outer suburbs and countryside where the stars thin out until giving way to relatively starless intergalactic space. Indeed, the anticenter of the Milky Way lies not far from the star El Nath (Beta Tauri) where Taurus meets Auriga. While the hazy band of the Milky Way is still visible through Auriga and Taurus, it’s thin and anemic compared to summer’s billowy star clouds.
The summertime Milky Way from Scorpius to Cygnus is broader and brighter than the winter version because we face toward the galactic center at nightfall. Credit: Stephen Bockhold
At nightfall in July and August, we face toward the galaxy’s center where 30,000 light years worth of stars, star clouds and nebulae stack up to fatten the Milky Way into a bright, chunky arch on summer evenings compared to winter’s thin gruel.
The slanting winter Milky Way touches many of the familiar, bright constellations of December. This map shows the sky facing southeast around 11 o’clock local time in early December or 9 p.m. in late December. Source: Stellarium
The winter Milky Way starts east of brilliant Sirius and grazes the east side of Orion before ascending into Gemini and Auriga and arching over into the western sky to Cassiopeia’s “W”. Binoculars and telescopes resolve it into individual stars and star clusters and help us appreciate what a truly beautiful and rich place our galactic home is.
Few sights that impress us with the scope and scale of where we live than seeing the Milky Way under a dark sky during the silence of a winter night. Picture Earth and yourself as members of that glowing carpet of stars, and when you can’t take the cold anymore, enjoy the delicious pleasure of stepping inside to unwrap and warm up. You’ve been on a long journey.
Researchers work in the Antarctic polar night during a storm (Credit: Stefan Hendricks, Alfred Wegner Institute)
Some day, human explorers will land a spacecraft on the surface of Europa, Enceladus, Titan, or some other icy world and investigate first-hand the secrets hidden beneath its frozen surface. When that day comes — and it can’t come too soon for me! — it may look a lot like this.
One of a series of amazing photos by Stefan Hendricks taken during the Antarctic Winter Ecosystem & Climate Study (AWECS), a study of Antarctica’s sea ice conducted by the Alfred Wegener Institute in Germany, the image above shows researchers working on the Antarctic ice during a winter snowstorm. It’s easy to imagine them on the night-side surface of Europa, with the research vessel Polarstern standing in for a distant illuminated lander (albeit rather oversized).
Hey, one can dream!
One of the goals of the campaign, called CryoVex, was to look at how ESA’s CryoSat mission can be used to understand the thickness of sea ice in Antarctica. The extent of the Antarctic sea ice in winter is currently more than normal, which could be linked to changing atmospheric patterns.
Antarctica’s massive shelves of sea ice in winter are quite dramatic landscapes, and remind us that there are very alien places right here on our own planet.
See this and more photos from the mission on the ESA website (really, go check them out!)
