Category Archives: Solar Science

Eyes in the Sky, Solar Science

Video: Watch the Moon cross the face of Earth

Great views of the Moon transiting across the face of the Earth have been taken by the DSCOVR science spacecraft, which was launched to the Earth-Sun Lagrange point L-1 back in February on a SpaceX Falcon 9 rocket.

 From a Million Miles: The Moon Crossing the Face of Earth

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This image shows the far side of the moon, illuminated by the sun, as it crosses between the DSCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credits: NASA/NOAA

Click for larger image.

A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the moon as it moved in front of the sunlit side of Earth last month. The series of test images shows the fully illuminated “dark side” of the moon that is never visible from Earth.

The images were captured by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope on the DSCOVR satellite orbiting 1 million miles from Earth. From its position between the sun and Earth, DSCOVR conducts its primary mission of real-time solar wind monitoring for the National Oceanic and Atmospheric Administration (NOAA).

EPIC maintains a constant view of the fully illuminated Earth as it rotates, providing scientific observations of ozone, vegetation, cloud height and aerosols in the atmosphere. Once EPIC begins regular observations next month, the camera will provide a series of Earth images allowing study of daily variations over the entire globe. About twice a year the camera will capture the moon and Earth together as the orbit of DSCOVR crosses the orbital plane of the moon.

These images were taken between 3:50 p.m. and 8:45 p.m. EDT on July 16, showing the moon moving over the Pacific Ocean near North America. The North Pole is in the upper left corner of the image, reflecting the orbital tilt of Earth from the vantage point of the spacecraft.

The far side of the moon was not seen until 1959 when the Soviet Luna 3 spacecraft returned the first images. Since then, several NASA missions have imaged the lunar far side in great detail. The same side of the moon always faces an earthbound observer because the moon is tidally locked to Earth. That means its orbital period is the same as its rotation around its axis.

In May 2008 NASA’s Deep Impact spacecraft captured a similar view of Earth and the moon from a distance of 31 million miles away. The series of images showed the moon passing in front of our home planet when it was only partially illuminated by the sun.

EPIC’s “natural color” images of Earth are generated by combining three separate monochrome exposures taken by the camera in quick succession. EPIC takes a series of 10 images using different narrowband spectral filters — from ultraviolet to near infrared — to produce a variety of science products. The red, green and blue channel images are used in these color images.

Combining three images taken about 30 seconds apart as the moon moves produces a slight but noticeable camera artifact on the right side of the moon. Because the moon has moved in relation to the Earth between the time the first (red) and last (green) exposures were made, a thin green offset appears on the right side of the moon when the three exposures are combined. This natural lunar movement also produces a slight red and blue offset on the left side of the moon in these unaltered images.

The lunar far side lacks the large, dark, basaltic plains, or maria, that are so prominent on the Earth-facing side. The largest far side features are Mare Moscoviense in the upper left and Tsiolkovskiy crater in the lower left. A thin sliver of shadowed area of moon is visible on its right side.

“It is surprising how much brighter Earth is than the moon,” said Adam Szabo, DSCOVR project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Our planet is a truly brilliant object in dark space compared to the lunar surface.”

Once EPIC begins regular observations next month, NASA will post daily color images of Earth to a dedicated public website. These images, showing different views of the planet as it rotates through the day, will be available 12 to 36 hours after they are acquired.

DSCOVR is a partnership between NASA, NOAA and the U.S. Air Force with the primary objective of maintaining the nation’s real-time solar wind monitoring capabilities, which are critical to the accuracy and lead time of space weather alerts and forecasts from NOAA.

For more information about DSCOVR, visit: www.nesdis.noaa.gov/DSCOVR

dscovrepicmoontransitfull[1]Click for larger image.

 

Solar Science

Solar cycle update

The number of sunspots decreased significantly in February as the current peak in the solar cycle winds down: Sunspots crash in February – Behind The Black –

ISES Solar Cycle Sunspot Number Progression - NOAA
Solar Science, Space Systems

Video: 5 year time-lapse of the sun with images from the Solar Dynamics Observatory

NASA Goddard marks the five year anniversary of  the launch of the Solar Dynamics Observatory with some cool videos:

New Videos Highlight NASA SDO’s Fifth Anniversary

February 11, 2015 marks five years in space for NASA’s Solar Dynamics Observatory or SDO, which provides incredibly detailed images of the Earth-facing side of the sun 24 hours a day. Capturing an image almost once per second, SDO has provided an unprecedentedly clear picture of how massive explosions on the sun grow and erupt ever since its launch on Feb. 11, 2010. The imagery is also captivating, allowing one to watch the constant ballet of solar material through the sun’s atmosphere, the corona.

In honor of SDO’s fifth anniversary, NASA has released two videos showcasing highlights from the last five years of sun watching. The first is a time lapse of the past five years. Different colors represent different wavelengths of extreme ultraviolet light, ultraviolet light, and visible light, which in turn correspond to solar material at different temperatures.  Additionally SDO returns solar magnetic field data that helps scientists study solar activity.

The second video showcases highlights from the last five years. Watch the movie to see giant clouds of solar material hurled out into space, the dance of giant loops hovering in the corona, and huge sunspots growing and shrinking on the sun’s surface.

The imagery in both videos is an example of the kind of data that SDO provides to scientists. By watching the sun in different wavelengths – and therefore different temperatures – scientists can watch how material courses through the corona, which holds clues to what causes eruptions on the sun, what heats the sun’s atmosphere up to 1,000 times hotter than its surface, and why the sun’s magnetic fields are constantly on the move. SDO also measures fluctuations in the sun’s extreme ultraviolet output, which provides the majority of energy for heating Earth’s upper atmosphere.

“There have now been more than 2,000 scientific papers published based on SDO data,” said Dean Pesnell, project scientist for SDO at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “SDO has also led to wonderful international collaborations, with the data being shared and used all over the world.”

Five years into its mission, SDO continues to send back tantalizing imagery to incite scientists’ curiosity. For example, in late 2014, SDO captured imagery of the largest sun spots seen since 1995 as well as a torrent of intense solar flares. Solar flares are bursts of light, energy and X-rays. They can occur by themselves or can be accompanied by what’s called a coronal mass ejection, or CME, in which a giant cloud of solar material erupts off the sun, achieves escape velocity and heads off into space. In this case, the sun produced only flares and no CMEs, which, while not unheard of, is somewhat unusual for flares of that size. Scientists are looking at that data now to see if they can determine what circumstances might have led to flares eruptions alone.

This mission has touched us on many levels; it evokes a sense of wonder when we see these beautiful images;” said Lika Guhathakurta, SDO program scientist at NASA Headquarters in Washington, DC. “It stokes our curiosity and it connects us personally to the deepest mysteries—from the warmth we feel on our skin when we walk outside on a sunny day to the distant reaches of the cosmos.”

Goddard built, operates and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C. SDO is the first mission of NASA’s Living with a Star Program. The program’s goal is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society.

For more on SDO, visit: www.nasa.gov/sdo

Rockets, Solar Science, Space Science

Video: Space weather satellite on SpaceX rocket

Here’s a DNEWS  report on the space weather data gathering DSCOVR spacecraft, which SpaceX is hoping to launch today: