Cold Snap Up North
Skytalk
by WHYY
3y ago
NASA’s InSight Mars lander keeps daily records of weather conditions at the Elysium Planitia landing site on the red planet. Last week saw daytime highs from 8 to 15 degrees Fahrenheit; lows fell to -139 degrees. Seasons are twice as long on Mars as on Earth because the Martian year is 687 days; almost double an Earth year. Mars doesn’t have months like we have months though. Our concept is based on a lunar orbit. Mars’ moons orbit much faster – Phobos every 8 hours, Deimos every 30 hours; so well over 2,000 orbits per 30 day ‘month’ for Phobos and over 500 orbits per ‘month’ for Deimos. InSig ..read more
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Older than Dirt
Skytalk
by WHYY
3y ago
Stardust discovered in a meteorite that landed in Australia more than 50 years ago is up to three billion years older than our solar system. These remnants are left over from ancient stars that populated this region of the galaxy prior to the birth of our sun, some 4.5 billion years ago. These particles got swept up in planet formation and/or hitched a ride to Earth on asteroids that have been in circulation ever since. Dating was determined from an element, Neon-21, which is derivative of cosmic ray-bombarded silicon carbide. Higher proportion of Neon-21 indicates the silicon carbide was drif ..read more
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Taking a Telescope to Galileo
Skytalk
by WHYY
3y ago
Today is Galileo’s 456th birth anniversary. His iconoclastic reputation overshadows his basic raison d’etre at the time – to make a buck. He was a struggling teacher who worked in the ‘gig economy’ of Renaissance Italy. Galileo wasn’t born to a high place in society; he wasn’t a politician, his parents were not rich and his father actually wanted his son to become a physician. He really wanted to be a mathematician. He eventually ditched medical school and became a university math instructor where he began to investigate physics of motion. A colleague informed him of a new optic device he’d se ..read more
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Coming Attractions
Skytalk
by WHYY
3y ago
Astronomers observing white dwarf stars see spectrographic signatures of previously orbiting gas giant planets. Our gas giants (Jupiter and Saturn) will possibly do the same – leave signatures of their existence on our White Dwarf sun long after all the inner planets are gone and the outer planets are transformed. Not to worry – this won’t happen for some eight billion years. Bid adieu to the Spitzer Space Telescope! Named after astrophysicist Lyman Spitzer (in 1965 he first proposed what would later become the Hubble Space Telescope), the Spitzer Space Telescope was launched in 2003. Expected ..read more
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49ers, Chiefs & Punxsutawney Phil
Skytalk
by WHYY
3y ago
49ers, Chiefs & Punxsutawney Phil This Superbowl Sunday coincides with Groundhog Day – the first cross-quarter day of 2020 (half-way between winter and spring). Punxsutawney Phil may be the most famous groundhog in the U.S., but he isn’t the most accurate. The four-legged creature only has a 39 percent accuracy, according to Stormfax Almanac’s data. Phil sees his shadow about 85 percent of the time (which portends six more weeks of winter) Extreme Global Warming! – Different process altogether from Earth. KELT-9b is a gas giant planet orbiting a star 670 light years away from earth. As a ..read more
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Our Stellar Neighbor Beckons
Skytalk
by WHYY
3y ago
The dim red star Proxima Centauri, 4.2 lightyears from Earth, is known to have an EarthPlus-planet in the star’s habitable zone. Now a second planet has been detected, but this one is 5.8 times the mass of our planet and orbits its star only once every five years. Unfortunately, it’s also too far from the cool star to be warm enough for liquid water. So, it’s not habitable – at least for us. Which leads to a proposal to send 1,000 tiny spacecraft – really just a computer chip attached to a solar sail driven by ground-based lasers with 100 gigawatts of power to drive them along. The idea is tha ..read more
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Elementary
Skytalk
by WHYY
3y ago
Supernovae are known as element factories, but astronomers are now discovering that merging neutron stars and fast-spinning supernovae may also be capable of creating variants of the elements heavier than iron. Heavy elements are created through nuclear fusion. Venus shines in the west after sunset. Mars brightens up the east at 6:00am for sunrise, now sliding towards Antares of Scorpius. Good opportunity to compare the two. Could the concept of ‘dark energy’ all be a big mistake? Next week, Skytalk examines new data showing that the key assumption made in the discovery of dark energy is in er ..read more
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Imaging the Unimaginable
Skytalk
by WHYY
3y ago
This year’s highlights in the world of astronomy include: 1) An image of the shadow of a black hole resembles an ‘orange doughnut.’ A supermassive Black Hole was seen in silhouette against the background of its surrounding accretion disk. 2) Liquid water is identified at Saturn’s moon Enceladus. 3) The New Horizons spacecraft flew past Pluto in 2016, then flew past an even more distant object on New Year’s Day 2019 – a double-lobed Kuiper Belt object now known as Arrokoth. Its shape resembles the BB-8 droid from the recent ‘Star Wars’ chapters. It features a small circle atop a larger circle ..read more
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Mark the Moment
Skytalk
by WHYY
3y ago
We’ve arrived at the point in our solar orbit where the number of hours of sunlight are at a minimum for us in the North, and and conversely at a maximum for those in the Southern hemisphere. Sunset is already three minutes later than its earliest time, but we’re still losing time at sunrise, and the latest sunrise doesn’t come until early January. Hanukkah begins tomorrow at sunset, Christmas Day is Wednesday, and the first day of Kwanzaa is Thursday the 26th. The Moon and Mars can be seen in the December 23 predawn sky at 6:20 am, and Venus is swiftly pulling away from sinking Saturn in the ..read more
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Let There Be Light (but not too much)
Skytalk
by WHYY
3y ago
SpaceX will coat one side of a satellite to reduce brightness interference when observing from Earth. They intend to test one unit on the next deployment. There will be thousands of Starlink satellites joining the already tens of thousands of pieces of space junk. We need to develop a plan to clean up and fast! The European Space Agency will test a ‘space grab’ tech to start to clean up space. ‘Clear Space-1’ is designed to reach a dead satellite, grab it, and drag it down into a fiery re-entry destruction. So it’s slow and expensive, but it’s an emerging business as the future will certainly ..read more
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