On September 27, BBC has published the prequel of “Blue Planet II”. Like “The Blue Planet”, which was premiered on 12 September 2001, it is narrated by Sir David Attenborough, the English broadcaster and naturalist. The exclusive track was developed by the German composer and record producer Hans Zimmer and the English rock band Radiohead.
Launched on October 15, 1997, NASA’s Cassini spacecraft (see notes 1) went into orbit around Saturn on July 1, 2004. Since then, it has taken thousands of photos of Saturn, the second-largest planet in the Solar System, its prominent rings, and moons. And on September 15, 2017, Cassini plunged into Saturn’s atmosphere and disintegrated. Here are the 20 most beautiful photos that the spacecraft has sent back to Earth during its 13-year voyage around the gas giant.
Cassini was destroyed by diving into Saturn’s atmosphere on September 15, 2017. This method of disposal was planned to avoid potential biological contamination of Saturn’s moons, since Titan, Enceladus, and other icy moons of Saturn may harbor oceans and alien life.
External cameras on the International Space Station captured views during its overhead passes of Hurricane Irma. The most intense Atlantic hurricane observed in over a decade, Hurricane Irma was an extremely powerful tropical cyclone, which became a Category 5 hurricane on September 5. It reached peak intensity with 185 mph (295 km/h) winds on September 6.
Its category dropped to 3 as it passed along Cuba, but, while crossing over warm waters between Cuba and the Florida Keys, it became stronger again and rose to Category 4 on September 10. Then dropped back to Category 3 by the time it made a second Florida landfall on Marco Island. Hurricane Irma weakened to a Category 2 hurricane later that day. As of September 12, it is not a hurricane anymore, weakened to a tropical storm, and then a tropical depression six days after its peak intensity (see notes 1).
Sometimes, a wondering star comes and passes so close to our Sun. Now, thanks to data provided by the Gaia spacecraft, we can know the occurrence of these close passing-bys in advance.
This potentially dangerous event last happened about 70,000 years ago, a wandering binary stellar system passed through the Solar System‘s Oort cloud (see notes 1), within 120,000 AU (0.58 pc; 1.9 ly) of the Sun. 70,000 years is just a blink of an eye compared to the Earth’s age, which is 4.543 billion years. Our ancestors were about to leave Africa at that time. The binary system is dubbed as Scholz’s Star (see notes 2), after its discoverer.
Comets perturbed from the Oort cloud would require roughly 2 million years to get to the inner Solar System. So, in the distant future, some of these comets may hit the Earth and cause mass extinctions, like the “dinosaur killer” Chicxulub impactor which impacted a few miles from the present-day town of Chicxulub in Mexico around 66 million years ago.
On Monday, August 21, an estimated 2 million to 7.4 million Americans traveled to see the first total solar eclipse in 99 years to go coast to coast in the United States, which went from Lincoln Beach, Oregon, to Charleston, South Carolina. But, some of them were unlucky, as the weather was overcast in some places. But, luckily for them (and for us), NASA captured some amazing and beautiful images of the eclipse and published them on their website.
On February 22, 2017, NASA astronomers have announced that seven Earth-sized planets have been discovered around an ultra-cool dwarf star named TRAPPIST-1 which is located around 39 light-years from the Earth. And what’s more – three of them are orbiting their star in the habitable zone. Now scientists find clues that TRAPPIST-1 system may contain water.
Then, an international team of astronomers led by the Swiss astronomer Vincent Bourrier from the Observatoire de l’ Université de Genève used the NASA/ESA Hubble Space Telescope to estimate whether there might be water on the planets of TRAPPIST-1 system.
Now, on August 31, 2017, the team announced that their findings suggest that “the outer planets of the system might still harbor substantial amounts of water”, including the three planets within the habitable zone of the star – TRAPPIST-1e, f, and g. This result lends further weight to the possibility that these planets may indeed be habitable.
On September 1, 2017, a potentially hazardous asteroid named 3122 Florence skimmed past Earth from a mere 4.4 million miles (7 million km) distance. The huge asteroid, which is around 2.7 mile (4.4 km) wide, was the “biggest object passed this close to Earth since the NASA program to detect and track near-Earth asteroids began”, according to Paul Chodas, manager of the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory in Pasadena, California. The close flyby was captured with an amateur astronomer using an 80 mm F5 Apo telescope and a Canon 6D camera, and published on YouTube.
You may have heard it has been said that if the Earth were shrunk down to the size of a billiard ball, it would be smoother than it. In other words, the Earth is smoother than a billiard ball. Is that true?
Back in 2008, on the “Bad Astronomy” blog on discovermagazine.com, in the article titled “Ten things you don’t know about the Earth“, Phil Plait wrote about that, and said “…according to the World Pool-Billiard Association, a pool ball is 2.25 inches in diameter and has a tolerance of +/- 0.005 inches.” and after making some calculations, he concluded that “… the urban legend is correct. If you shrank the Earth down to the size of a billiard ball, it would be smoother.”
The Earth rotates from west to east with a linear velocity of 465.1013 m/s (1674.365 km/h) at the equator. But what would happen if the Earth stopped rotating abruptly? Online magazine Tech Insider presented a video demonstrating the development of events in this case.
Why do we see only one side of the Moon? You have probably heard references being made to the “dark side” of the Moon – there’s even a Pink Floyd album with that name. But there’s no “dark side” of the moon because our satellite is not illuminated by the Earth, it is illuminated by the Sun. All the surface of the