The Sun has a lot of rhythm and goes through different cycles of activity. The most well-known cycle might be the Schwabe cycle, which has an 11-year cadence. But what about cycles with much longer time scales? How can scientists understand them?
As it turns out, the Sun has left some hidden clues in tree rings.
Continue reading “Tree Rings Reveal 1,000 Years of Solar Activity”
Like Earth, Mars has experienced periods of extreme glaciation or ice sheet coverage, which are known as ice ages. As these ice ages come and go, glaciers expand and contract along the planet’s surface, grinding huge boulders down to smaller rocks. By examining the size of boulders and rocks at specific locations on Mars, we should be able to understand the history of the Martian ice ages.
A new study did just that.
Continue reading “Mars has Been Through Many Ice Ages in the Last Billion Years”
Humanity can have a love/hate relationship with itself, but there’s no denying that we’re the pinnacle of evolution on Earth as things stand now. But it took an awfully long time for evolution to produce beings such as we. Several times, life had to drag itself back from near annihilation.
The largest extinction setback was the Permian-Triassic extinction, also called the “Great Dying,” some 252 million years ago. Up to 96% of all marine species and 70% of terrestrial vertebrate species went extinct.
Continue reading “Scientists Think They Know What Caused the Deadliest Mass Extinction in the History of the Earth”
We can thank NASA’s New Horizons spacecraft for opening our eyes up to Pluto’s complexity. On July 14th, 2015, the spacecraft came within 12,500 km (7,800 mi) of the dwarf planet. During the flyby, New Horizons was able to characterize Pluto’s atmosphere and its surface.
Among the things New Horizons saw was a region of snowcapped mountains.
Continue reading “Pluto has Snowcapped Mountains, But Why?”
Modern astronomical telescopes are extraordinarly powerful. And we keep making them more powerful. With telescopes like the Extremely Large Telescope and the Giant Magellan Telescope seeing first light in the coming years, our astronomical observing power will be greater than ever.
But a new commentary says that climate change could limit the power of our astronomical observatories.
Continue reading “Climate Change is Making the Atmosphere Worse for Astronomy”
Hundreds of millions of years ago, Earth went through two episodes of severe glaciation. These two episodes—the Sturtian and the Marinoan glaciations—occured during the Earth’s Cryogenian Period. The Cryogenian lasted from about 720 million to 635 million years ago.
The phenomenon is called “Snowball Earth” and both instances of it happened in pretty quick succession. And while a planet encased in ice and snow sounds devastating, these episodes may have paved the way for the development of complex life.
The question is, what caused the Earth to freeze over like that?
Continue reading “Did Snowball Earth Happen Because of a Sudden Drop in Sunlight?”
Orbiters are giving us a chance to study the surface of Mars closely, and some of the features that pop to prominence are dry river channels. There are over 10,000 of them. But a new study suggests that glaciers on ancient Mars are responsible for many of them.
According to the study, those glaciers and the water flowing under them are resonsible for carving out some of those riverbeds, rather than free-flowing rivers.
Continue reading “Martian Features Were Carved by Glaciers, not Flowing Rivers”
An iceberg that calved off of from a larger ice formation has spent three years floating on the ocean near Antarctica. The iceberg broke off of the Larsen Ice Shelf in mid-July 2017. It’s been battered and split up into three pieces, but it’s still going.
Continue reading “This Giant Iceberg Has Been Sailing the Southern Seas for Three Years Now”
If—or hopefully when—we cut our Greenhouse Gas (GHG) emissions, we won’t notice much difference in the climate. The Earth’s natural systems take time to absorb carbon from the atmosphere. We may have to wait decades for the temperatures to drop.
Of course, that doesn’t mean we shouldn’t do it. It’s just that we have to temper our expectations a little.
Continue reading “Even If We Cut Greenhouse Gas Emissions Tomorrow, it Would Take Decades for the Earth to Start Cooling Again”
It seems almost certain that an asteroid impact wiped out the dinosaurs. But only almost. Another competing theory won’t completely go away: the extinction-by-volcano theory.
A new study from the UK piles more evidence on the asteroid side of the debate, while adding a new volcanic twist. These researchers say that volcanic activity actually helped life recover from the asteroid strike.
Continue reading “It Was Almost Certainly an Asteroid Impact that Wiped Out the Dinosaurs. In Fact, Volcanoes Might Have Helped Life Recover”