New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Antarctic Circle

The Antarctic Circle is one of the five major circles or parallels of latitude that mark maps of the Earth. It is at latitude 66 degrees 33′ 39″ south of the equator (in 2000; like its northern counterpart, the Arctic Circle, the value is currently slowly decreasing over time, pushing the Antarctic Circle southwards with about 15 m per year). For everywhere within the Antarctic Circle, there is at least twenty-four hours of continuous daylight on the Summer Solstice in December, and at least twenty-four hours of continuous nighttime on the Winter Solstice in June. That is to say, one whole day during which the sun does not set, and one whole day during which the sun does not rise. This is because the earth is tilted at a 23.5 degree angle, and during the winter solstice, the southern hemisphere is tilted away from the Sun, meaning that the antarctic circle is completely tilted away from the Sun, hence it experiences 24 hour nighttime, and vice versa.

Related Stories
 


Earth & Climate News

August 24, 2025

A new study reveals that the majority of Earth’s species stem from a few evolutionary explosions, where new traits or habitats sparked rapid diversification. From flowers to birds, these bursts explain most of the planet’s ...
As the ozone layer recovers, it’s also intensifying global warming. Researchers predict that by 2050, ozone will rank just behind carbon dioxide as a driver of heating, offsetting many of the benefits from banning ...
Industrial forests, packed with evenly spaced trees, face nearly 50% higher odds of megafires than public lands. A lidar-powered study of California’s Sierra Nevada reveals how dense plantations feed fire severity, but also shows that proactive ...
Planting more trees can help cool the planet and reduce fire risk—but where they are planted matters. According to UC Riverside researchers, tropical regions provide the most powerful climate benefits because trees there grow year-round, absorb ...
Kelp forests bounce back faster from marine heatwaves when shielded inside Marine Protected Areas. UCLA researchers found that fishing restrictions and predator protection strengthen ecosystem resilience, though results vary by ...
Scientists found that Great Salt Lake’s chemistry and water balance were stable for thousands of years, until human settlement. Irrigation and farming in the 1800s and a railroad causeway in 1959 ...
NASA-backed simulations reveal that meltwater from Greenland’s Jakobshavn Glacier lifts deep-ocean nutrients to the surface, sparking large summer blooms of phytoplankton that feed the Arctic food ...
NASA and ISRO s NISAR satellite has just reached a major milestone: the successful deployment of its enormous 39-foot antenna reflector in orbit. Folded up like an umbrella during launch, the reflector is now fully extended and ready to support ...
With its two tiny CubeSats, NASA’s PREFIRE mission is capturing invisible heat escaping from Earth, offering clues to how ice, clouds, and storms influence the climate system. The insights could lead to better weather forecasts and a deeper ...
Roughly two-thirds of all atmospheric methane, a potent greenhouse gas, comes from methanogens. Tracking down which methanogens in which environment produce methane with a specific isotope signature is difficult, however. UC Berkeley researchers ...
Rising CO₂ levels will make the upper atmosphere colder and thinner, altering how geomagnetic storms impact satellites. Future storms could cause sharper density spikes despite lower overall density, increasing drag-related ...
When a massive 8.8 magnitude earthquake struck off Russia’s Kamchatka Peninsula, NASA and CNES’s SWOT satellite captured a rare and detailed picture of the tsunami that followed. Recorded just ...

Latest Headlines

updated 12:56 pm ET