エピソード

  • 885-Dark Sky Network

    885-Dark Sky Network
    2026/02/06
    Around the world those who value the natural night sky are evaluating the effects of light pollution. In addition to impairing astronomy and star gazing the past 100 years of increasing light pollution is proving to be harmful to human health and the natural world upon which we all depend. The purpose of the Dark Sky Network is monitor and facilitate the mitigation of the harmful effects of light pollution.
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    2 分
  • 374E-408-Earth's Pet Rock

    374E-408-Earth's Pet Rock
    2026/02/03
    On it's gravitational leash, Earth's pet space rock, 2016 HO3, accompanies us at a distance of between 38 and 100 times the Moon's distance from Earth as we both travel about the Sun. As this tiny asteroid orbits the Sun it spends about half of it's time inside the Earth's orbit where it moves faster and passes ahead of us and the other half of it's yearly path outside of our orbit which causes it to lag behind our home planet. Since it's discovery little has been known about Earth's pet space rock leaving some to speculate that perhaps it is an old rocket booster or other piece of space junk. To answer this question, Dr. Vishnu Reddy of the University of Arizona's Lunar and Planetary Laboratory headed up a team of astronomers who used the University of Arizona's Large Binocular Telescope and the Discovery Channel's Telescope to determine some of it's properties. This team of researchers found that 2016 HO3 is indeed a natural object about 100 to 300 feet in diameter, rotates about once every 28 minutes, and is made of material similar to meteorites which have landed on Earth. Our pet space rock, 2016 HO3, has apparently been in it's present relationship to Earth for a hundred years and is likely to remain so for hundreds of years to come. Even though 2016 HO3 is not gravitationally bound to the Earth, the combination of the Sun's and Earth's gravitational pulls keeps it relatively near making it easy to reach and thus is an ideal candidate for visits by human or robotic spacecraft.
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    2 分
  • 884-Turkeys and Asteroids

    884-Turkeys and Asteroids
    2026/01/30
    Since in its early history the Earth’s surface was hot and lifeless it is likely that asteroids formed in the same era as Bennu delivered the raw materials for life when they impacted our home planet long ago
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    2 分
  • 373E-407-Plant Companionship

    373E-407-Plant Companionship
    2026/01/27
    On Earth, human life is enabled by plants which provide us with calories, vitamins, fuel, medicines, and oxygen to breathe. In addition, recent scientific studies indicate that plant cultivation reduces anxiety and depression and has a positive influence on diabetes, heart disease, obesity, and longevity. Perhaps this is the reason that 80% of the cultivated plant species on planet Earth are not used for any food related purpose. On long duration space missions astronauts live in close quarters isolated from the natural world where the basic activities like eating, sleeping, and attending to bodily functions are difficult and stress producing. Recent research conducted on the International Space Station suggests that space gardening helps astronauts to cope with the sterile space craft interior, allows them to combat boredom, as well as some of the other negative psychological effects of their long period of confinement. Specific examples of International Space Station gardens include astronaut Scott Kelly's first zinnia to bloom in space and astronaut Peggy Whitson's small crop of space soybeans. For many thousands of years people making long journeys have taken plants for food and recreation with them. It is likely that when humans travel to Mars they will continue this practice. The plants that Mars explorers take with them will provide a source of fresh fruits and vegetables , fresh air to breathe, and perhaps a psychological benefit that is crucial to the success of their mission.
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    2 分
  • 883-Theia

    883-Theia
    2026/01/23
    In the distant past things in our solar system were very much more wild and violent than they are today. 4.5 billion years ago a Mars sized object called Theia impacted Earth producing our Moon. Scientists are able research this event using the current chemical compositions of the Earth and Moon.
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    2 分
  • 372E-406-Close Ones

    372E-406-Close Ones
    2026/01/20
    In less than 24 hours, while observing with the Catalina Sky Survey's 60 inch telescope on Mt. Lemmon, Arizona , I discovered two 25 foot diameter space rocks that theoretically can pass less than a quarter of the Moon's distance from us. After I posted my discovery observations on the Minor Planet Center's Near Earth Object Confirmation page one of them received immediate attention, as an incoming object, and was tracked by observers at 14 different observatories around the world. Scientists at the Minor Planet Center used these data to calculate it's 926 day orbital path around the Sun, estimate it's size, and give it the name 2017 TH5. 36 hours after I first spotted 2017 TH5 streaking through the night sky it came to less than 60,000 miles from the surface of our planet traveling at 7.6 miles per second. 8 hours and 49 minutes later it passed less than half a lunar distance from the surface of our moon. If 2017 TH5 would have been on an impact trajectory with Earth humans would have had time to prepare for a spectacular light show. Approximately once every 5 years a tiny asteroid like 2017 TH5 enters our atmosphere exploding at an altitude about 3 times higher than airliners fly releasing the energy of about 5,000 tons of TNT. Asteroid hunters are well on our way towards being able to issue a warning to stay away from doors and windows should a small space rock be discovered to be on an impact trajectory with planet Earth.
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    2 分
  • 882-David’s Goliath PHA

    882-David’s Goliath PHA
    2026/01/16
    My Catalina Sky Survey teammate David Rankin was asteroid hunting in the evening twilight with our 60 inch telescope on Mt. Lemmon Arizona when he spotted an unknown object in the constellation of Lyra. The largest telescopes on Earth will likely track David's discovery until it becomes too faint to observe in 2027 and catch it again when it again becomes bright enough to track in 2050. Fortunately it is extremely unlikely that it will strike Earth when it again comes close to our home planet in 2052.
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    2 分
  • 371E-405-Kiwi Nights

    371E-405-Kiwi Nights
    2026/01/13
    New Zealand's 4.5 million people are concentrated in three major population centers which to various degrees suffer from the modern plague of light pollution. However, most of New Zealand's large rural areas and land reserves, covering an area as large as the UK, have unpolluted natural night skies. A completely unique place to experience New Zealand's natural night sky is the Aotea [ Ah - yoh - tee - ah]-Great Barrier Island International Dark Sky Sanctuary. It encompasses New Zealand's, 110 square mile, sixth largest island, which is located about 62 miles from central Auckland. It is easily accessible by boat or a short airline flight. The island's 1000 residents are employed by agriculture and tourism. They value the natural night sky and function without externally generated electricity or street lights and fully support the preservation of their prestine night sky. In the daytime Great Barrier Island offers wonderful beaches and hikes. When the sun sets the night sky becomes alive with its own natural lights. Night sky measurements by Auckland Astronomer Nalayini [ Na - laa - i - ni] Davies and her collaborators have proved that the Great Barrier Island's natural night skies are second to none on planet Earth. Using the unaided eye, a set of binoculars, or a small telescope an observer on the Great Barrier Island is treated to spectacular views of the center of the Milky Way, the clouds of Magellan the nearest galaxies to us, the nearest stars, as well as numerous star clusters, meteors, comets, and other wonders of the natural night sky. Perhaps this unique spot deserves a place on your bucket list.
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    2 分