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
March 18, 2026
Mar. 18, 2026 Pink granite boulders sitting mysteriously atop Antarctica’s Hudson Mountains have led scientists to a stunning discovery: a hidden granite mass buried beneath Pine Island Glacier, stretching nearly 100 km wide and 7 km thick. By dating the rocks ...
Mar. 18, 2026 AI’s growing energy use sounds alarming, but its global climate impact may be far smaller than expected. Researchers found that while AI consumes huge amounts of electricity, it barely moves the needle on overall emissions. The real impact is more ...
Mar. 15, 2026 The asteroid impact that wiped out the dinosaurs didn’t keep life down for long. New research shows that microscopic plankton began evolving into new species within just a few thousand years—and possibly in under 2,000 years—after the ...
Mar. 14, 2026 Spiders and insects may not be fan favorites, but they are vital to the health of ecosystems—and scientists barely know how they’re doing. Researchers found that nearly 90% of North America’s insect and arachnid species have no conservation ...
Mar. 12, 2026 Researchers have uncovered a universal pattern showing how temperature affects life on Earth. Across thousands of species—from microbes to reptiles—performance rises gradually with warming until an optimal temperature is reached, after which it ...
Mar. 12, 2026 Decades of data from over 80,000 great tits reveal that extreme weather can shape the fate of baby birds. Cold snaps soon after hatching and heavy rain later in development shrink nestling body mass and reduce survival odds. But moderate warm spells ...
Mar. 11, 2026 As deep-sea waters warm, scientists expected trouble for the microbes that help keep ocean chemistry in balance. Instead, researchers found that Nitrosopumilus maritimus can adapt to warmer, iron-limited conditions by using iron more efficiently. ...
Mar. 9, 2026 Global warming has picked up speed in the past decade, according to a new analysis from the Potsdam Institute for Climate Impact Research (PIK). By removing short term natural influences such as El Niño, volcanic eruptions, and solar cycles from ...
Mar. 6, 2026 Scientists have discovered a newly identified marine fungus that can infect and kill toxic algae responsible for harmful blooms. The microscopic parasite, named Algophthora mediterranea, attacks algae such as Ostreopsis cf. ovata, which produces ...
Mar. 5, 2026 Ocean temperatures may be quietly protecting the world from a global drought catastrophe. By analyzing more than a century of climate data, researchers discovered that droughts rarely spread across the planet at the same time, affecting only about ...
Mar. 5, 2026 A sweeping new study of more than 2,000 insect species reveals a troubling reality: many insects may be far less capable of coping with rising temperatures than scientists once hoped. Researchers found that while some species living at higher ...
Mar. 4, 2026 Northern wildfires may be more dangerous for the climate than they appear. Researchers found that fires in boreal forests can burn deep into peat soils, releasing ancient carbon stored for hundreds ...
Latest Headlines
updated 12:56 pm ET
Mar. 15, 2026 A new detection method called “Jerk” could dramatically improve how scientists forecast volcanic eruptions. By using a single broadband ...
Mar. 14, 2026 Scientists may have finally solved the mystery of strange plume-like structures hidden deep inside the Greenland ice sheet. New research suggests ...
Mar. 12, 2026 Scientists at Curtin University have uncovered a new way to read the deep history of Earth’s landscapes using microscopic zircon crystals from ancient beach sands. These incredibly durable minerals ...
Mar. 11, 2026 A long-running debate about the Silverpit Crater beneath the North Sea has finally been resolved. Scientists now confirm it formed when a roughly 160-meter asteroid struck the seabed about 43–46 ...
Mar. 7, 2026 Gravity may seem constant, but it actually varies across the planet—and one of the strangest places is Antarctica, where gravity is slightly weaker than expected. Scientists have traced this ...
Mar. 3, 2026 Fusion energy may be one of the most promising clean power sources of the future—but only if scientists can precisely measure the extreme, fast-moving plasmas that make it possible. A new U.S. ...
Mar. 2, 2026 K’gari’s iconic lakes have existed for tens of thousands of years—but they haven’t always been full. New research shows that about 7,500 ...
Mar. 2, 2026 Even in the ultra-dry Atacama Desert, tiny soil-dwelling nematodes are thriving in surprising diversity. Scientists found that biodiversity increases with moisture and altitude shapes which species ...
Mar. 1, 2026 For the first time ever, scientists have uncovered a vast field of tektites in Brazil — mysterious glassy fragments forged when a powerful ...
Feb. 28, 2026 A popular climate theory suggested that melting Antarctic glaciers would release iron into the ocean, sparking algae blooms that pull carbon dioxide from the air. New field data from West Antarctica ...