Reference Terms
from Wikipedia, the free encyclopedia
Axial tilt
Axial tilt is an astronomical term regarding the inclination angle of a planet's rotational axis in relation to a perpendicular to its orbital plane. It is also called axial inclination or obliquity. The axial tilt is expressed as the angle made by the planet's axis and a line drawn through the planet's center perpendicular to the orbital plane.
The axial tilt may equivalently be expressed in terms of the planet's orbital plane and a plane perpendicular to its axis. In our solar system, the Earth's orbital plane is known as the ecliptic, and so the Earth's axial tilt is officially called the obliquity of the ecliptic.
The Earth has an axial tilt of about 23 degrees 27’. The axis is tilted in the same direction throughout a year; however, as the Earth orbits the Sun, the hemisphere (half part of earth) tilted away from the Sun will gradually come to be tilted towards the Sun, and vice versa. This effect is the main cause of the seasons (see effect of sun angle on climate). Whichever hemisphere is currently tilted toward the Sun experiences more hours of sunlight each day, and the sunlight at midday also strikes the ground at an angle nearer the vertical and thus delivers more heat.
Related Stories
1
2
Earth & Climate News
May 11, 2026
May 10, 2026 A team at the University of Hong Kong has developed a new “super steel” that can survive the harsh conditions needed to make green hydrogen from seawater. The material uses an unexpected double-protection mechanism that resists corrosion far ...
May 10, 2026 A colossal underwater volcano in the South Pacific may have revealed a surprising new weapon against climate change. After the 2022 eruption of Hunga Tonga–Hunga Ha’apai, scientists detected enormous amounts of formaldehyde in the atmosphere — ...
May 10, 2026 Scientists have uncovered strong evidence that a major Atlantic Ocean current system tied to global climate is weakening. The slowdown has been detected across a vast region of the North Atlantic ...
May 10, 2026 Scientists have uncovered a hidden Antarctic threat that could accelerate global sea level rise far faster than expected. Deep beneath floating ice shelves, long channels carved into the ice appear ...
May 8, 2026 Beneath the beauty of coral reefs lies a hidden universe of microbes unlike anything scientists expected. Each coral species supports its own specialized microbial partners, many of which have never ...
May 6, 2026 Cumberland, B.C. is reimagining its coal mining past as a clean energy opportunity. Water trapped in abandoned mine tunnels could be used in a geothermal system to heat and cool buildings efficiently and with minimal emissions. The project could ...
May 6, 2026 Southern Alaska’s winter finale delivered a spectacular atmospheric display, captured by a NASA satellite. Cold Arctic air flowing over warmer ocean waters created long bands of clouds, swirling vortex patterns, and even a compact polar storm with ...
May 4, 2026 Greenland’s ice sheet is now melting in ways never seen before, with extreme events becoming more frequent, widespread, and intense. Since 1990, meltwater production has skyrocketed, and most record-breaking events have occurred in recent years. ...
May 4, 2026 Scientists are using sunlight to turn plastic waste into clean fuels like hydrogen, offering a breakthrough solution to both pollution and energy challenges. While still in development, the approach could transform trash into a valuable resource for ...
May 3, 2026 Long before humans spread across the globe, a deadly disease may have quietly shaped where our ancestors lived—and even how we evolved. New research reveals that malaria didn’t just threaten early human survival; it actively pushed populations ...
May 2, 2026 Crabs’ famous sideways walk may trace back to a single evolutionary moment 200 million years ago. Researchers found that most modern crabs inherited this trait from one ancestor—and never looked back. The movement likely gave them an edge, ...
May 2, 2026 Two of the most dangerous fault systems on the U.S. West Coast may be more connected than scientists once thought. New research suggests the Cascadia subduction zone and the San Andreas fault can “sync up,” triggering earthquakes within minutes ...
Latest Headlines
updated 12:56 pm ET
May 2, 2026 A centuries-old vision of a mechanical volcano has finally erupted into reality, as two University of Melbourne engineering students recreated a design first imagined in 1775 by volcanology ...
May 1, 2026 Scientists have uncovered a tiny wall-dwelling spider named Pikelinia floydmuraria, inspired by Pink Floyd. Despite its size, it’s a fierce predator that hunts ants much larger than itself and ...
Apr. 30, 2026 Australia’s famous Twelve Apostles didn’t just erode into existence—they were slowly pushed up from the ocean floor by powerful tectonic forces over millions of years, new research reveals. ...
Apr. 30, 2026 Deep beneath the Southern Ocean, a quiet but alarming shift is underway: warm water is creeping closer to Antarctica, and scientists are now seeing it clearly for the first time. By combining decades ...
Apr. 29, 2026 For the first time, scientists have watched a subduction zone literally fall apart beneath the ocean floor. Using advanced seismic imaging, they found the Juan de Fuca plate splitting into fragments ...
Apr. 29, 2026 New experiments suggest that freezing and thawing on early Earth may have helped primitive cell-like structures grow and evolve. Tiny lipid bubbles behaved very differently depending on their ...
Apr. 28, 2026 A new study suggests Neanderthals didn’t go extinct simply because of climate change or competition with Homo sapiens. Instead, the key difference may have been social connectivity—Homo sapiens ...
Apr. 27, 2026 The mysterious collapse of the Maya civilization may not have been driven solely by drought after all. New evidence from lake sediments in Guatemala reveals that one key city, Itzan, enjoyed a stable ...
Apr. 27, 2026 A mysterious “golden orb” found more than two miles deep in the Gulf of Alaska left scientists baffled for over two years, sparking wild ...
Apr. 27, 2026 A major new study finds that living in pesticide-heavy environments could raise cancer risk by up to 150%, even when the chemicals are considered “safe” on their own. The research suggests these ...