Venus Transit
Image Credit & Copyright: Chris Hetlage
via APOD
Info-source: Occurring in pairs separated by over a hundred years, there have now been only eight transits of Venus since the invention of the telescope in 1608. The next will be in December of 2117. But many modern telescopes and cameras were trained on this week’s Venus transit, capturing the planet in rare silhouette against the Sun. In this sharp telescopic view from Georgia, USA, a narrowband H-alpha filter was used to show the round planetary disk against a mottled solar surface with dark filaments, sunspots, and prominences. The transit itself lasted for 6 hours and 40 minutes. Historically, astronomers used timings of the transit from different locations to triangulate the distance to Venus, while modern astronomers actively search for planets that transit distant suns.

Venus Transit
Image Credit & Copyright: Chris Hetlage
via APOD
Info-source: Occurring in pairs separated by over a hundred years, there have now been only eight transits of Venus since the invention of the telescope in 1608. The next will be in December of 2117. But many modern telescopes and cameras were trained on this week’s Venus transit, capturing the planet in rare silhouette against the Sun. In this sharp telescopic view from Georgia, USA, a narrowband H-alpha filter was used to show the round planetary disk against a mottled solar surface with dark filaments, sunspots, and prominences. The transit itself lasted for 6 hours and 40 minutes. Historically, astronomers used timings of the transit from different locations to triangulate the distance to Venus, while modern astronomers actively search for planets that transit distant suns.

Flying Over the Earth at Night
Credits: Gateway to Astronaut Photography, NASA; Compilation: Bitmeizer (YouTube)
via APOD

Info-Source: Many wonders are visible when flying over the Earth at night. A compilation of such visual spectacles was captured recently from the International Space Station (ISS) and set to rousing music. Passing below are white clouds, orange city lights, lightning flashes in thunderstorms, and dark blue seas. On the horizon is the golden haze of Earth’s thin atmosphere, frequently decorated by dancing auroras as the video progresses. The green parts of auroras typically remain below the space station, but the station flies right through the red and purple auroral peaks. Solar panels of the ISS are seen around the frame edges. The ominous wave of approaching brightness at the end of each sequence is just the dawn of the sunlit half of Earth, a dawn that occurs every 90 minutes.

Angry Sun Erupting
via APOD

Info-source: It’s one of the baddest sunspot regions in years. Active Region 1429 may not only look, to some, like an angry bird — it has thrown off some of the most powerful flares and coronal mass ejections of the current solar cycle. The extended plumes from these explosions have even rained particles on the Earth’s magnetosphere that have resulted in colorful auroras. Pictured above, AR 1429 was captured in great detail in the Sun’s chromosphere three days ago by isolating a color of light emitted primarily by hydrogen. The resulting image is shown in inverted false color with dark regions being the brightest and hottest. Giant magnetically-channeled tubes of hot gas, some longer than the Earth, are known as spicules and can be seen carpeting the chromosphere. The light tendril just above AR 1429 is a cool filament hovering just over the active sunspot region. As solar maximum nears in the next few years, the increasingly wound and twisted magnetic field of the Sun may create even more furious active regions that chirp even more energetic puffs of solar plasma into our Solar System.

Angry Sun Erupting
via APOD

Info-source: It’s one of the baddest sunspot regions in years. Active Region 1429 may not only look, to some, like an angry bird — it has thrown off some of the most powerful flares and coronal mass ejections of the current solar cycle. The extended plumes from these explosions have even rained particles on the Earth’s magnetosphere that have resulted in colorful auroras. Pictured above, AR 1429 was captured in great detail in the Sun’s chromosphere three days ago by isolating a color of light emitted primarily by hydrogen. The resulting image is shown in inverted false color with dark regions being the brightest and hottest. Giant magnetically-channeled tubes of hot gas, some longer than the Earth, are known as spicules and can be seen carpeting the chromosphere. The light tendril just above AR 1429 is a cool filament hovering just over the active sunspot region. As solar maximum nears in the next few years, the increasingly wound and twisted magnetic field of the Sun may create even more furious active regions that chirp even more energetic puffs of solar plasma into our Solar System.

Saturn: Shadows of a Seasonal Sundial 
via APOD
Credits: Cassini Imaging Team, ISS, JPL,ESA, NASA

Info-source: Saturn’s rings form one of the larger sundials known. This sundial, however, determines only the season of Saturn, not the time of day. In 2009, during Saturn’s last equinox, Saturn’s thin rings threw almost no shadows onto Saturn, since the ring plane pointed directly toward the Sun. As Saturn continued in its orbit around the Sun, however, the ring shadows become increasingly wider and cast further south. These shadows are not easily visible from the Earth because from our vantage point near the Sun, the rings always block the shadows. The above image was taken in August by the robotic Cassini spacecraft currently orbiting Saturn. The rings themselves appear as a vertical bar on the image right. The Sun, far to the upper right, shines through the rings and casts captivatingly complex shadows on south Saturn, on the image left. Cassini has been exploring Saturn, its rings, and its moons since 2004, and is expected to continue until at least the maximum elongation of Saturn’s shadows occurs in 2017.

Saturn: Shadows of a Seasonal Sundial
via APOD
Credits: Cassini Imaging Team, ISS, JPL,
ESA, NASA

Info-source: Saturn’s rings form one of the larger sundials known. This sundial, however, determines only the season of Saturn, not the time of day. In 2009, during Saturn’s last equinox, Saturn’s thin rings threw almost no shadows onto Saturn, since the ring plane pointed directly toward the Sun. As Saturn continued in its orbit around the Sun, however, the ring shadows become increasingly wider and cast further south. These shadows are not easily visible from the Earth because from our vantage point near the Sun, the rings always block the shadows. The above image was taken in August by the robotic Cassini spacecraft currently orbiting Saturn. The rings themselves appear as a vertical bar on the image right. The Sun, far to the upper right, shines through the rings and casts captivatingly complex shadows on south Saturn, on the image left. Cassini has been exploring Saturn, its rings, and its moons since 2004, and is expected to continue until at least the maximum elongation of Saturn’s shadows occurs in 2017.

Saturn Portrait Rings Unlit
Credit: Gordan Ugarkovic

Saturn Portrait Rings Unlit
Credit: Gordan Ugarkovic

Atlantis Reflection
Credit: NASA, Bill Ingalls

Info-source: Space shuttle orbiter Atlantis left planet Earth on Friday, July 8, embarking on the STS-135 mission to the International Space Station. The momentous launch was the final one in NASA’s 30 year space shuttle program that began with the launch of the first reusable spacecraft on April 12, 1981. In this reflective prelaunch image from July 7, Atlantis stands in a familiar spot on the Kennedy Space Center’s pad 39A, after an early evening roll back of the pad’s Rotating Service Structure. The historic orbital voyages of Atlantis have included a Hubble Space Telescope servicing mission, deployment of Magellan, Galileo, and the Compton Gamma-ray Observatory, and seven trips to the Russian space station Mir. Scheduled to dock once again with the International Space Station on Sunday, Atlantis has now made its 33rd and final trip to orbit.

Atlantis Reflection
Credit: NASA, Bill Ingalls

Info-source: Space shuttle orbiter Atlantis left planet Earth on Friday, July 8, embarking on the STS-135 mission to the International Space Station. The momentous launch was the final one in NASA’s 30 year space shuttle program that began with the launch of the first reusable spacecraft on April 12, 1981. In this reflective prelaunch image from July 7, Atlantis stands in a familiar spot on the Kennedy Space Center’s pad 39A, after an early evening roll back of the pad’s Rotating Service Structure. The historic orbital voyages of Atlantis have included a Hubble Space Telescope servicing mission, deployment of Magellan, Galileo, and the Compton Gamma-ray Observatory, and seven trips to the Russian space station Mir. Scheduled to dock once again with the International Space Station on Sunday, Atlantis has now made its 33rd and final trip to orbit.

Rhea and Titan
Credit: NASA/JPL/Space Science Institute

Info-source: Here is just a simply way-cool picture from Cassini taken in 2009, showing the Saturnian moon Rhea peeking out from behind the much larger Titan […] Rhea is a little over 1500 km (900 miles) across, and Titan 5150 km (3100 miles). However, in this shot, Rhea was almost two and a half times farther away than her big sister, so it looks smaller than it really is. Titan has a thick atmosphere, which is pretty obvious in the picture, while Rhea is basically a ginormous iceball.

Rhea and Titan
Credit: NASA/JPL/Space Science Institute

Info-source: Here is just a simply way-cool picture from Cassini taken in 2009, showing the Saturnian moon Rhea peeking out from behind the much larger Titan […] Rhea is a little over 1500 km (900 miles) across, and Titan 5150 km (3100 miles). However, in this shot, Rhea was almost two and a half times farther away than her big sister, so it looks smaller than it really is. Titan has a thick atmosphere, which is pretty obvious in the picture, while Rhea is basically a ginormous iceball.

Solstice Moonrise, Cape Sounion
Credit & Copyright: Anthony Ayiomamitis (TWAN)

Info-source: June 2008. Astronomer Anthony Ayiomamitis recorded this dramatic picture of the solstice Full Moon rising above Cape Sounion, Greece. The twenty-four hundred year old Temple of Poseidon lies in the foreground, also visible to sailors on the Aegean Sea. In this well-planned single exposure, a telescopic lens makes the Moon loom large, but even without optical aid casual skygazers often find the Full Moon looking astonishingly large when seen near the horizon. That powerful visual effect is known as the Moon Illusion.

Solstice Moonrise, Cape Sounion
Credit & Copyright: Anthony Ayiomamitis (TWAN)

Info-source: June 2008. Astronomer Anthony Ayiomamitis recorded this dramatic picture of the solstice Full Moon rising above Cape Sounion, Greece. The twenty-four hundred year old Temple of Poseidon lies in the foreground, also visible to sailors on the Aegean Sea. In this well-planned single exposure, a telescopic lens makes the Moon loom large, but even without optical aid casual skygazers often find the Full Moon looking astonishingly large when seen near the horizon. That powerful visual effect is known as the Moon Illusion.

The boiling, erupting Sun
Credit & Copyright: Alan Friedman

Info-source: This phenomenal picture shows our nearest star in the light of hydrogen, specifically what astronomers call Hα (H-alpha). In this picture you can see sunspots, giant convection cells, and the gas that follows magnetic loops piercing the Sun’s surface. When we see them against the Sun’s surface they’re called filaments, and when they arc against the background sky on the edge of the Sun’s disk they’re called prominences.

The boiling, erupting Sun
Credit & Copyright: Alan Friedman

Info-source: This phenomenal picture shows our nearest star in the light of hydrogen, specifically what astronomers call Hα (H-alpha). In this picture you can see sunspots, giant convection cells, and the gas that follows magnetic loops piercing the Sun’s surface. When we see them against the Sun’s surface they’re called filaments, and when they arc against the background sky on the edge of the Sun’s disk they’re called prominences.

Eclipsed Moonlight
Credit & Copyright: Javier Algarra

Info-source: The June 15 total lunar eclipse was one of the longest in recent years. It was also one of the darkest, but not completely dark. Even during totality, a somber, red lunar disk could be seen in the starry night sky, reflecting reddened light falling on to its surface. Seen from a lunar perspective, the ruddy illumination is from all the sunsets and sunrises around the edges of a silhouetted Earth. In this sharp portrait of the eclipsed Moon from Granada, Spain, the Moon’s edge reflects a bluish tinge as well as it emerges from Earth’s umbral shadow. The bluer light is still filtered through Earth’s atmosphere, but originates in rays of sunlight passing through layers high in the upper stratosphere. That light is colored by ozone that absorbs red light and transmits bluer hues.

Eclipsed Moonlight
Credit & Copyright: Javier Algarra

Info-source: The June 15 total lunar eclipse was one of the longest in recent years. It was also one of the darkest, but not completely dark. Even during totality, a somber, red lunar disk could be seen in the starry night sky, reflecting reddened light falling on to its surface. Seen from a lunar perspective, the ruddy illumination is from all the sunsets and sunrises around the edges of a silhouetted Earth. In this sharp portrait of the eclipsed Moon from Granada, Spain, the Moon’s edge reflects a bluish tinge as well as it emerges from Earth’s umbral shadow. The bluer light is still filtered through Earth’s atmosphere, but originates in rays of sunlight passing through layers high in the upper stratosphere. That light is colored by ozone that absorbs red light and transmits bluer hues.