Why astronauts float in space

We see images and videos from the International Space Station (ISS) where astronauts floating in the space freely. That’s because they’re in the space, so there is no gravitational force of Earth there, right?

Wrong.

The International Space Station is in Low Earth OrbitSee notes 1 with an altitude of between 330 and 435 km (205 and 270 mi). It is so close to the Earth that on a clear day easily visible to the naked eye from the ground as it is the third brightest object in the sky (NASA has actually launched a new interactive map at its Spot the Station web site). At that altitude, the Earth’s gravity is about 90 percent of what it is on the planet’s surface – still pretty strong, right? To reduce the gravity of the Earth by a factor of one million, one needs to be at a distance of 6 million kilometers (around 3,728,227 miles) from the Earth – more than fifteen times the distance between the Earth and Moon.

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Japanese Man Lives With Pet Caiman

Another unique and interesting friendship between a wild reptile and a man, like the famous story of Chito and Pocho. This Japanese man, named Nobumitsu Murabayashi, keeps a giant caiman as a pet, and even walks with him in the town center of Kure City, Hiroshima, Japan – with the permission of the city hall.

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Ancient carvings show a comet hit Earth 13,000 years ago

Ancient symbols carved into stone at Göbekli Tepe (an archaeological site in Turkey) tell the story of a big comet impact more than 13,000 years ago, scientists think. The devastating impact triggered a mini ice-age which drove many mammals weighing more than 40 kg to extinction.

According to an article published by New Scientist, carvings made on a pillar known as the “Vulture Stone” in Göbekli Tepe suggest that a swarm of comet fragments hit the Earth in around 11000 BC.

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Earth Between the Rings of Saturn

A beautiful image published by NASA, taken by the unmanned Cassini-Huygens spacecraft, shows the Earth between the rings of Saturn. The image is taken on April 12, 2017.

“Consider again that dot [Earth]. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every ‘superstar,’ every ‘supreme leader,’ every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.” 

Carl Sagan, Pale Blue Dot: A Vision of the Human Future in Space
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The Black Marble: Earth from Space at Night

The first new global map of Earth from space at night since 2012 has been released by the NASA scientists. The nighttime look of our planet is dubbed the “Black Marble”. But why?

On December 7, 1972, the crew of Apollo 17 spacecraft en route to the Moon took a photo of Earth from the space, at a distance about 45,000 kilometers (28,000 miles). This image, with the official NASA designation AS17-148-22727, became known as “The Blue Marble”.

In fact, it was not the first clear image of Earth taken from the space – similar photos had already been taken as early as 1967. But, the 1970s were the scene of a big surge in environmental activism. For example, on April 22, 1970, the first “Earth Day” organized by Gaylord Nelson, former senator of Wisconsin, and Denis Hayes, Harvard graduate student. Millions of people gather in the United States for the event.

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Jeff’s Earth – Amazing HD Video from ISS

On his most recent trip the International Space Station (Expedition 48),recently-retired NASA astronaut Jeff Williams has recorded a great HD video of Earth using an Ultra High Definition video camera.

Here in the video titled “Jeff’s Earth” below, he shares some of those images and talks about the beauty of the planet, the variety of things to see, and the value of sharing that perspective with everyone who can’t go to orbit in person.

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7 Earth-Sized Planets Found Orbiting Nearby Star – 3 of them are in the Habitable Zone

On February 22, 2017, NASA has announced that seven Earth-sized planets have been observed by NASA’s Spitzer Space Telescope around TRAPPIST-1, a tiny, nearby, an ultra-cool dwarf star located 39 light-years (12 parsecs; 370 petametres) away from Earth in the constellation Aquarius. The good news is: three of these planets are firmly in the habitable zone. The new discovery may be a great breakthrough in the search for extraterrestrial life.

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What would the Earth be like if humans never existed

Around 4 millions year ago, the ancestors of humans and chimpanzees diverged, genetic evidence suggests. What, if Chimpanzee–human last common ancestor(1) would suddenly die before giving birth to any babies? What would the Earth be like if humans never existed?

Researchers from Aarhus University in Denmark demonstrated that the Earth without humans would resemble Serengeti(2), a geographical region in Africa which hosts the largest terrestrial mammal migration in the world.

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Water found on the exoplanet 51 Pegasi b

Scientists spotted water in the atmosphere of 51 Pegasi b, one of the first exoplanets ever been discovered. It is around 50 light years away – so we can call it a “nearby” exoplanet – and it is in the constellation of Pegasus.

51 Pegasi b has not marked a breakthrough in astronomical research for the first time: back in 1995, it was the first exoplanet to be discovered orbiting a main-sequence star. The first confirmed exoplanet discovery came in 1992 when several terrestrial-mass planets orbiting the pulsar PSR B1257+12.

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How the darkness and the cold killed the (non-avian) dinosaurs

Now we have a computer simulation of how the afterward effects of famous Chicxulub asteroid (estimated to be 10 km/6.2 mi) wide) killed the non-avian dinosaurs (and also a wide range of other species). On January 13, 2017, an article titled “Baby, it’s cold outside: Climate model simulations of the effects of the asteroid impact at the end of the Cretaceous”, published by the Climate scientists of Potsdam Institute for Climate Impact Research (PIK), revealed a detailed model of what happened to the atmosphere and the climate after the Chicxulub impact.

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