July 26, 2017

Saturn's Rings

Saturn's Rings

Although the rings lack the many colors of the rainbow, they arc across the sky of Saturn. From equatorial locations on the planet, they'd appear very thin since they would be seen edge-on. Closer to the poles, the rings would appear much wider; in some locations (for parts of the Saturn's year), they would even block the Sun for part of each day.

This view looks toward the sunlit side of the rings from about 19 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on April 10, 2017.

The view was obtained at a distance of approximately 680,000 miles (1.1 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 128 degrees. Image scale is 43 miles (69 kilometers) per pixel.

Image Credit: NASA/JPL-Caltech/Space Science Institute
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21339

Spiral Galaxy NGC 4248

Spiral Galaxy NGC 4248

This beautiful clump of glowing gas, dark dust, and glittering stars is the spiral galaxy NGC 4248, located about 24 million light-years away in the constellation of Canes Venatici (The Hunting Dogs).

This image was produced by the NASA/ESA Hubble Space Telescope as it embarked upon compiling the first Hubble ultraviolet “atlas”, for which the telescope targeted 50 nearby star-forming galaxies. A sample spanning all kinds of different morphologies, masses, and structures. Studying this sample can help us to piece together the star-formation history of the Universe.

By exploring how massive stars form and evolve within such galaxies, astronomers can learn more about how, when, and where star formation occurs, how star clusters change over time, and how the process of forming new stars is related to the properties of both the host galaxy and the surrounding interstellar medium (the “stuff” that fills the space between individual stars).

This image is formed of observations from Hubble’s Wide Field Camera 3.

Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1730a/

Kinked Loop Stretching Between Two Active Regions

Kinked Loop Stretching Between Two Active Regions

Numerous arches of magnetic field lines danced and swayed above a large active region over about a 30-hour period (July 17-18, 2017). We can also see the magnetic field lines from the large active region reached out and connected with a smaller active region. Those linked lines then strengthened (become brighter), but soon began to develop a kink in them and rather swiftly faded from view. All of this activity is driven by strong magnetic forces associated with the active regions. The images were taken in a wavelength of extreme ultraviolet light.

Image Credit: NASA/GSFC/Solar Dynamics Observatory
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21838