That’s here; that’s home; that’s us. The image above shows what Earth looked like to NASA’s Cassini spacecraft on April 13, 2017 as it flew past Saturn’s night-shadowed A and F rings. At the time the raw images were captured Saturn and Cassini were about 889.6 million miles (1.43 billion kilometers) from Earth. From that distance our entire world—and everyone on it—is just another tiny light in the dark.
One of the favorite allegations by those who continue to be skeptical of the Apollo moon landings is that there are no stars visible in the photographs taken by the astronauts while they were “supposedly” on the Moon. Now while there’s a rather short but succinct list of why that’s the case (and feel free to review those reasons here) the truth is that there ARE stars visible in photographs taken from the Moon—photographs taken in ultraviolet light during the penultimate Apollo 16 mission in April of 1972.
On March 17, 2002, a pair of satellites nicknamed “Tom” and “Jerry” launched aboard a Russian Rockot vehicle from the Plesetsk Cosmodrome in Russia. It was the start of the Gravity Recovery and Climate Experiment, aka GRACE, a partnership mission between NASA and the German space agency (DLR) to map Earth’s gravity field and how it changes over time due to the movement and variations of surface and ground water. Originally planned to be a five-year mission, GRACE has now been continuously operating in orbit for over 15 years, and has revealed much about what’s been happening to the water on—and in—our planet.
Supernovas are some of the most powerful and energetic events in the entire Universe. When a dying star explodes you wouldn’t want to be anywhere nearby—fresh elements are nice and all, but the energy and radiation from a supernova would roast any planets within tens if not hundreds of light-years in all directions. Luckily for us we’re not in an unsafe range of any supernovas in the foreseeable future, but there was a time not very long ago (in geological terms) that these stellar explosions occurred nearby (in astronomical terms) and in 2016 scientists found the “smoking gun” evidence at the bottom of the ocean.
What’s more, the arrival of the iron-rich fallout from those stellar explosions seems to coincide with ancient global temperature changes*, the most recent dated near the start of the last major ice age which brought lower sea levels, widespread glaciation…and eventually the rise of the first modern humans.
Read more at Universe Today here: Nearby Supernovas Showered Earth With Iron
*Note: the changes in climate referred to here are not the same as the climate change we are witnessing today. Not only are we now seeing rapid warming of land and sea temperatures globally, but today’s forcings are the result of increasing greenhouse gases like carbon dioxide in the atmosphere—not radioactive iron from exploding stars.
If you’re in love with space then you’ll fall head over heels for this: it’s a picture of Earth taken from the Voyager 1 spacecraft after it passed the orbit of Pluto back in 1990—on Valentine’s Day, no less. That image of our planet from almost 4 billion miles away inspired Carl Sagan to write his famous “Pale Blue Dot” passage, which reminds us that we are all just riding on “a mote of dust suspended in a sunbeam.”