ultraviolet light

Solar System: Things to Know This Week

Reaching out into space yields benefits on Earth. Many of these have practical applications — but there’s something more than that. Call it inspiration, perhaps, what photographer Ansel Adams referred to as nature’s “endless prospect of magic and wonder." 

Our ongoing exploration of the solar system has yielded more than a few magical images. Why not keep some of them close by to inspire your own explorations? This week, we offer 10 planetary photos suitable for wallpapers on your desktop or phone. Find many more in our galleries. These images were the result of audacious expeditions into deep space; as author Edward Abbey said, "May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view.”

1. Martian Selfie

This self-portrait of NASA’s Curiosity Mars rover shows the robotic geologist in the “Murray Buttes” area on lower Mount Sharp. Key features on the skyline of this panorama are the dark mesa called “M12” to the left of the rover’s mast and pale, upper Mount Sharp to the right of the mast. The top of M12 stands about 23 feet (7 meters) above the base of the sloping piles of rocks just behind Curiosity. The scene combines approximately 60 images taken by the Mars Hand Lens Imager, or MAHLI, camera at the end of the rover’s robotic arm. Most of the component images were taken on September 17, 2016.

2. The Colors of Pluto

NASA’s New Horizons spacecraft captured this high-resolution, enhanced color view of Pluto on July 14, 2015. The image combines blue, red and infrared images taken by the Ralph/Multispectral Visual Imaging Camera (MVIC). Pluto’s surface sports a remarkable range of subtle colors, enhanced in this view to a rainbow of pale blues, yellows, oranges, and deep reds. Many landforms have their own distinct colors, telling a complex geological and climatological story that scientists have only just begun to decode.

3. The Day the Earth Smiled

On July 19, 2013, in an event celebrated the world over, our Cassini spacecraft slipped into Saturn’s shadow and turned to image the planet, seven of its moons, its inner rings — and, in the background, our home planet, Earth. This mosaic is special as it marks the third time our home planet was imaged from the outer solar system; the second time it was imaged by Cassini from Saturn’s orbit, the first time ever that inhabitants of Earth were made aware in advance that their photo would be taken from such a great distance.

4. Looking Back

Before leaving the Pluto system forever, New Horizons turned back to see Pluto backlit by the sun. The small world’s haze layer shows its blue color in this picture. The high-altitude haze is thought to be similar in nature to that seen at Saturn’s moon Titan. The source of both hazes likely involves sunlight-initiated chemical reactions of nitrogen and methane, leading to relatively small, soot-like particles called tholins. This image was generated by combining information from blue, red and near-infrared images to closely replicate the color a human eye would perceive.

5. Catching Its Own Tail

A huge storm churning through the atmosphere in Saturn’s northern hemisphere overtakes itself as it encircles the planet in this true-color view from Cassini. This picture, captured on February 25, 2011, was taken about 12 weeks after the storm began, and the clouds by this time had formed a tail that wrapped around the planet. The storm is a prodigious source of radio noise, which comes from lightning deep within the planet’s atmosphere.

6. The Great Red Spot

Another massive storm, this time on Jupiter, as seen in this dramatic close-up by Voyager 1 in 1979. The Great Red Spot is much larger than the entire Earth.

7. More Stormy Weather

Jupiter is still just as stormy today, as seen in this recent view from NASA’s Juno spacecraft, when it soared directly over Jupiter’s south pole on February 2, 2017, from an altitude of about 62,800 miles (101,000 kilometers) above the cloud tops. From this unique vantage point we see the terminator (where day meets night) cutting across the Jovian south polar region’s restless, marbled atmosphere with the south pole itself approximately in the center of that border. This image was processed by citizen scientist John Landino. This enhanced color version highlights the bright high clouds and numerous meandering oval storms.

8. X-Ray Vision

X-rays stream off the sun in this image showing observations from by our Nuclear Spectroscopic Telescope Array, or NuSTAR, overlaid on a picture taken by our Solar Dynamics Observatory (SDO). The NuSTAR data, seen in green and blue, reveal solar high-energy emission. The high-energy X-rays come from gas heated to above 3 million degrees. The red channel represents ultraviolet light captured by SDO, and shows the presence of lower-temperature material in the solar atmosphere at 1 million degrees.

9. One Space Robot Photographs Another

This image from NASA’s Mars Reconnaissance Orbiter shows Victoria crater, near the equator of Mars. The crater is approximately half a mile (800 meters) in diameter. It has a distinctive scalloped shape to its rim, caused by erosion and downhill movement of crater wall material. Since January 2004, the Mars Exploration Rover Opportunity has been operating in the region where Victoria crater is found. Five days before this image was taken in October 2006, Opportunity arrived at the rim of the crater after a drive of more than over 5 miles (9 kilometers). The rover can be seen in this image, as a dot at roughly the “ten o'clock” position along the rim of the crater. (You can zoom in on the full-resolution version here.)

10. Night Lights

Last, but far from least, is this remarkable new view of our home planet. Last week, we released new global maps of Earth at night, providing the clearest yet composite view of the patterns of human settlement across our planet. This composite image, one of three new full-hemisphere views, provides a view of the Americas at night from the NASA-NOAA Suomi-NPP satellite. The clouds and sun glint — added here for aesthetic effect — are derived from MODIS instrument land surface and cloud cover products.

Discover more lists of 10 things to know about our solar system HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

The magnetic field lines between a pair of active regions formed a beautiful set of swaying arches, seen in this footage captured by our Solar Dynamics Observatory on April 24-26, 2017. 

These arches, which form a connection between regions of opposite magnetic polarity, are visible in exquisite detail in this wavelength of extreme ultraviolet light. Extreme ultraviolet light is typically invisible to our eyes, but is colorized here in gold. 

Take a closer look: https://go.nasa.gov/2pGgYZt

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Seven Years of Tracking the Solar Cycle

Our sun is ever-changing, and a satellite called the Solar Dynamics Observatory has a front-row seat. 

On February 11, 2010, we launched the Solar Dynamics Observatory, also known as SDO. SDO keeps a constant eye on the sun, helping us track everything from sunspots to solar flares to other types of space weather that can have an impact on Earth.

After seven years in space, SDO has had a chance to do what few other satellites have been able to do – watch the sun for the majority of a solar cycle in 11 types of light.

The sun’s activity rises and falls in a pattern that lasts about 11 years on average. This is called the solar cycle.

Solar activity can influence Earth. For instance, it’s behind one of Earth’s most dazzling natural events – the aurora.

One of the most common triggers of the aurora is a type of space weather called a coronal mass ejection, which is a billion-ton cloud of magnetic solar material expelled into space at around a million miles an hour. 

When these clouds collide with Earth’s magnetic field, they can rattle it, sending particles down into the atmosphere and triggering the auroras. These events can also cause satellite damage and power grid strain in extreme cases. 

The sun is in a declining activity phase, so coronal mass ejections will be less common over the next few years, as will another one of the main indicators of solar activity – sunspots.

Sunspots are created by twisted knots of magnetic field. Solar material in these tangled regions is slightly cooler than the surrounding areas, making them appear dark in visible light.

The tangled magnetic field that creates sunspots also causes most solar activity, so more sunspots means more solar activity, and vice versa. Humans have been able to track the solar cycle by counting sunspots since the 17th century.  

Image: Houghton Library, Harvard University, *IC6.G1333.613ia

The peak of the sun’s activity for this cycle, called solar maximum, was in 2014. 

Now, we’re heading towards the lowest solar activity for this solar cycle, also known as solar minimum. As solar activity declines, the number of sunspots decreases. We sometimes go several days without a single visible sunspot.

But there’s much more to the story than sunspots – SDO also watches the sun in a type of light called extreme ultraviolet. This type of light is invisible to human eyes and is blocked by our atmosphere, so we can only see the sun this way with satellites.

Extreme ultraviolet light reveals different layers of the sun’s atmosphere, helping scientists connect the dots between the sunspots that appear in visible light and the space weather that impacts us here on Earth.

SDO keeps an eye on the sun 24/7, and you can see near real-time images of the sun in 11 types of light at sdo.gsfc.nasa.gov/data.

instagram

Demonstration of Fluorescence in Fluorite