Skytalk

Enjoy an earlier sunrise starting Sunday morning, when our area reverts to Eastern Standard Time.

The Kepler Planet Hunter is kaput! After nine-and-a-half years and 2,800 confirmed planetary discoveries in our Milky Way, Kepler finally ran out of fuel. It’s been placed in a safe, stable solar orbit. Its biggest contribution: the suggestion that every star has at least one planet. NASA’s Opportunity Rover on Mars might also be kaput, as it hasn’t radioed in since the summer’s dust storm on Mars.

Our sun, some 865,000 miles in diameter, rotates once every 30-35 days or so; fairly normal for a star like ours.

The naked eye is just fine – but if the night sky is clear this evening, the best way to view the moon is with a pair of binoculars, revealing craters, seas, bays and more. In addition, Saturn and Mars are still hanging in the early evening sky. The constellations Pegasus, Andromeda, Cassiopeia and Perseus are rising in the east.

Tomorrow marks the 95th year since attendees took in the first planetarium show, at the Deutches Museum in Munich, Germany. Actually, indoor depictions of the night sky go back to 1,500 B.C. in Egyptian tombs. The Adler Planetarium in Chicago was first in the United States in 1930. The Fels Planetarium at the Franklin Institute in Philadelphia opened four years later, as the second planetarium in the US.

Buried in the data from European Space Agency’s Gaia Survey satellite, astronomers from Leiden University in the Netherlands discovered 13 new stars whose hyper-velocities suggest they’ve interlopers from EXTRA-galactic sources (outside our Milky Way).

NASA’s Voyager 2 spacecraft, launched on August 20, 1977, is (perhaps) about to leave near-sun space, as evidenced by an uptick in cosmic ray detection. About 40,000 years from now, Voyager 1 (which launched 16 days after Voyager 2) will be closer to a star other than the Sun when it passes within 1.6 light-years of GJ 445, a red dwarf star currently in the constellation Camelopardalis.

Scientists who confirmed the existence of 2015 TG387 out beyond the Kuiper Belt believe its orbit offers the best evidence of the existence of the long-speculated Planet X in our solar system.

With clear skies during the week, a beautiful thin crescent moon can be seen in the pre-dawn sky.

Gaia, a galactic surveyor spacecraft, has caught our galaxy doing “the wave!” Studies of one billion stars show a wave-like motion in the stars of our galaxy’s arms. According to galactic structure theory, this shouldn’t be happening but it is. Why? A near-collision with the Sagittarius dwarf galaxy 200 million to 1 billion years ago imparted a gravitational shove that started “the wave.” When the galaxies collide again, our Milky Way will consume or incorporate the dwarf, one of the ways our galaxy got to be so big. Astronomers don’t see the arms doing the wave but they can trace the motions of the stars over the past billion years and interpret that it has been happening.

NASA celebrates its 60th anniversary on Monday. The agency was founded in 1958, after the Soviet launch of Sputnik, but was an outgrowth of the National Commission on Aeronautics, which was founded in 1915 when the United States needed to catch up to Europe in the field of aviation.

A group of researchers, including the Principle Investigator for the New Horizons program, Alan Stern, have found that after a review of 200 years of science literature, in only one instance has the ‘clear its orbit’ requirement ever been used to define an object as a planet. Further, the new team recommends that the definition of an object as a planet be based on the formation of the object itself rather than the ‘subject-to-external-influences’ dynamics of its orbit. As the 2006 IAU definition of a planet currently stands, its not really a definition of the object itself but all about that object’s relation to orbital dynamics that could change given the right circumstances, whereas the original formation of an object is fixed once the formation is complete. The most important factor: Is the object massive enough to pull itself into a spherical shape? If so, then, according to this group, the object is massive enough to initiate active geology – like differentiation, plate tectonics volcanism, etc. That’s not to say subsequent events might alter the make-up of the object, but its process, mechanism, and location of formation would never change. What does this mean practically? Pluto’s still a planet. Why? Because regardless of whether Pluto meets the other criteria of the 2006 IAU ruling on definition, “Pluto’s active geology and dynamism is what allows for it to have an interior ocean, a multilayered atmosphere, organic compounds and evidence of ancient lakes and multiple moons.” Some scientists now suggest that based on data gathered from the new Horizons fly-by mission, that only the Earth more geologically active than Pluto in our solar system. Only Earth is more geologically complex. And many other items in our solar system besides the Big Nine may belong to that class of items also. These items ‘know’ what they are, we are about the business of educating ourselves about them so we learn how to properly address them. While the IAU may have come up with a definition, nature forces us to constantly reconsider until our description is consistent with what the universe shows us.

Want to do a little astro age dating? Here’s an easy one – relative age dating on the moon. Bright white areas on the Moon’s surface are lunar highlands; wide, darker, smooth areas are lunar maria or seas. These are actually lava-filled basins created after meteor or asteroid impact. Lunar highlands are the older parts undisturbed after billions of years; the lava-filled basins are younger – relatively. Lave filled the basins after impact and overflowed.

Sunday, September 23rd marks the first day of Autumn!

52 years ago, the television show Star Trek premiered! It spawned a whole new approach to space exploration and had an impact on the world’s culture. NBC cancelled Star Trek in February 1969, 5 months before Apollo 11 landed on the moon.

Our Milky Way is thought to have originally formed shortly after the birth of the universe, 13.5 billion years ago. Built from the first stars and star clusters, gas from the galactic halo also contributed to the formation of the galaxy. Multiple galactic mergers helped trigger new star formation over and over again.

Turning to dark sky highlights, Mercury is visible low in the east at 5:45am; four planets in the evening sky for just another two week. Turning to constellations of note; Big Dipper in the North-West, Pegasus in the east, Hercules and the summer triangle right overhead; Libra(Jupiter), Scorpius, and Sagittarius(Saturn and Mars) hold the planets together.

NASA Science Visualization Labs’ Ernie Wright has created a beautiful visual compliment to De Bussey’s classic piano composition, ‘Claire De Lune’. Using images from NASA Lunar Reconnaissance Orbiter, which has been orbiting and photographing the moon in close-up high resolution since 2009, Wright’s video matches stunning images of the moon’s surface in a smooth-flowing visual montage that both reinvigorates the music and shows the moon’s changing appearance over the course of a lunar day.

Just about this time last year, about 154 million Americans went outside to experience a total solar eclipse. Next total across the US: April 8, 2024! Still have solar eclipse glasses? As long as they’re in good condition, you can use them to look at the sun safely anytime. Want to preserve them? Keep them in an envelope somewhere safe, like inside a book.

Here’s a mind-bender for you: one of Stephen Hawking’s best buds, physicist Roger Penrose, suggests that the ‘black hole doom’ from a previous universe would not only leave a dead universe with the ultra-compressed environment that might be found just before a ‘big bang’ event was to jump off, but it would leave traces of those shrinking black holes in our cosmic microwave background, the remnant of our universe’s birth. Sort of like a watermark in fine papers, these cosmologists are suggesting that as the past universe’s black holes evaporated, the massless photons and gravitons that escaped as Hawking radiation (Hawking suggested that black holes lose mass and energy slowly and shrink up), wouldn’t experience time or distance. It would be the Hawking radiation that would survive to create the ‘fossil’ print’ of the previous black hole. Penrose’s 2010 paper claiming to have identified Hawking points has been dismissed by others as random noise errors in their data. What’s next in this grand claim? More tests of course!