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Received — 2020年11月29日 ガジェット系

Researchers Calculate Earth is 2,000 Light-years Closer to the Milky Way's Black Hole

著者: EditorDavid
2020年11月29日 23:34
"Earth just got 7 km/s faster and about 2000 light-years closer to the supermassive black hole in the center of the Milky Way Galaxy," reports Phys.org: But don't worry, this doesn't mean that our planet is plunging towards the black hole. Instead the changes are results of a better model of the Milky Way Galaxy based on new observation data, including a catalog of objects observed over the course of more than 15 years by the Japanese radio astronomy project VERA. CNET explains: Over the last 15 years, a Japanese radio astronomy project, VERA, has been gathering data. Using a technique called interferometry, VERA gathered data from telescopes across Japan and combined them with data from other existing projects to create what is essentially the most accurate map of the Milky Way yet. By pinpointing the location and velocity of around 99 specific points in our galaxy, VERA has concluded that the supermassive black hole Sagittarius A, at the center of our galaxy, is actually 25,800 light-years from Earth — almost 2,000 light-years closer than what we previously believed. In addition, the new model calculates Earth is moving faster than we believed. Older models clocked Earth's speed at 220 kilometers (136 miles) per second, orbiting around the galaxy's centre. VERA's new model has us moving at 227 kilometers (141 miles) per second.

Read more of this story at Slashdot.

木星と土星、12月下旬には満月の見かけの直径の4分の1ほどまでに接近

著者: headless
2020年11月29日 17:25
最近は日没後の南西の空に並んで見える木星と土星だが、今後日を追うごとに近付いていき、12月下旬には最接近するそうだ(国立天文台 - ほしぞら情報)。

木星と土星が最接近するのは12月22日3時頃だが、日本では既に地平線の下にあるため、実際に最も近付いた状態で観察できるのは12月21日の日没後だという。2つの惑星は満月の見かけの直径の約4分の1にまで接近する。望遠鏡を使えば木星と土星に加え、木星のガリレオ衛星も同じ視野に捉えることが可能とのこと。なお、木星と土星は7月に相次いで地球との距離が最も近くなる衝を迎えていた。

12月17日時点では2つの惑星の距離が満月の見かけの直径程度だが、その左下に細い月が見えて美しい眺めになるそうだ。ただし、日没後の高度は低く、2時間あまりで沈んでしまうため観察可能な時間は限られる。国立天文台では南西の方角の見晴らしの良い場所での観察を推奨している。

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The ESA Starts a New Commercial Sector in Space: Removing Space Debris

著者: EditorDavid
2020年11月29日 07:24
Long-time Slashdot reader SonicSpike brings some big news from outer space. European Space Agency announced this week that they're signing "a €86 million ($102 million USD) contract with an industrial team led by the Swiss start-up ClearSpace SA to purchase a unique service: the first removal of an item of space debris from orbit" in the year 2025. "With this contract signature, a critical milestone for establishing a new commercial sector in space will be achieved..." In almost 60 years of space activities, more than 5,550 launches have resulted in some 42,000 tracked objects in orbit, of which about 23,000 remain in space and are regularly tracked. With today's annual launch rates averaging nearly 100, and with break-ups continuing to occur at average historical rates of four to five per year, the number of debris objects in space will steadily increase. ClearSpace-1 will demonstrate the technical ability and commercial capacity to significantly enhance the long-term sustainability of spaceflight... "This is the right time for such a mission..." says Luc Piguet, founder and CEO of ClearSpace. [I]n the coming years the number of satellites will increase by an order of magnitude, with multiple mega-constellations made up of hundreds or even thousands of satellites planned for low Earth orbit to deliver wide-coverage, low-latency telecommunications and monitoring services. The need is clear for a 'tow truck' to remove failed satellites from this highly trafficked region...." Supported within ESA's new Space Safety programme, the aim is to contribute actively to cleaning up space, while also demonstrating the technologies needed for debris removal. "Imagine how dangerous sailing the high seas would be if all the ships ever lost in history were still drifting on top of the water," says ESA Director General Jan Wörner. "That is the current situation in orbit, and it cannot be allowed to continue. ESA's Member States have given their strong support to this new mission, which also points the way forward to essential new commercial services in the future..." "NASA and ESA studies show that the only way to stabilise the orbital environment is to actively remove large debris items. Accordingly we will be continuing our development of essential guidance, navigation and control technologies and rendezvous and capture methods through a new project called Active Debris Removal/ In-Orbit Servicing — ADRIOS. The results will be applied to ClearSpace-1. This new mission, implemented by an ESA project team, will allow us to demonstrate these technologies, achieving a world first in the process." The ClearSpace-1 mission will target the Vespa (Vega Secondary Payload Adapter) upper stage left in an approximately 800 km by 660 km altitude orbit after the second flight of ESA's Vega launcher back in 2013. With a mass of 100 kg, the Vespa is close in size to a small satellite, while its relatively simple shape and sturdy construction make it a suitable first goal, before progressing to larger, more challenging captures by follow-up missions — eventually including multi-object capture. The ClearSpace-1 'chaser' will be launched into a lower 500-km orbit for commissioning and critical tests before being raised to the target orbit for rendezvous and capture using a quartet of robotic arms under ESA supervision. The combined chaser plus Vespa will then be deorbited to burn up in the atmosphere.

Read more of this story at Slashdot.

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