Earth science studies the Earth’s environments, climates, and composition, grouped into the atmosphere, lithosphere, biosphere, and hydrosphere. Geology, geophysics, and geography fall under the lithosphere. Paleontology studies extinct species, while oceanography, hydrology, and limnology study bodies of water. Meteorology and climatology study the atmosphere. Earth science is a broad term for any branch of science […]
Bleaching earth, a type of clay found in Asia, England, India, and the US, is processed for its absorbent, bleaching, and filtering properties. It is commonly used to remove color pigments from oils and other chemicals, filter impurities from petroleum products, and as an ingredient in beauty products and anti-diarrheal drugs. After use, spent bleaching […]
The Snowball Earth hypothesis suggests that the entire Earth was frozen during the Cryogenian period, with some scientists believing in a “Slushball Earth” scenario instead. The depletion of atmospheric carbon dioxide caused by continental drift is thought to have initiated the freeze, which could only be reversed by volcanic explosions releasing enough CO2 to cause […]
Alkaline earth metals are a group of six metallic elements found in the earth’s crust. They are hard, dense, and have high melting points due to their two valence electrons. They are also very reactive and have special uses, such as beryllium in x-ray machines, magnesium in medicine, calcium in construction, and radium in cancer […]
Fuller’s Earth is a superabsorbent form of aluminum silicate used for centuries to absorb dirt and oil. It is used in cat litter, filters, cleaners, and refining processes. It is also used in natural beauty products and in films to create explosions. Fuller’s Earth resembles clay in texture and shape, but is actually a superabsorbent […]
The ISS orbits the Earth 16 times a day, taking 90 minutes per orbit. It has traveled over 1.75 billion miles and takes two days to reach from Earth. Crews have occupied it since 2000. The International Space Station (ISS) takes about 90 minutes to orbit the Earth, which means it makes the trip around […]
Apollo 13 holds the record for the furthest humans have been from Earth, reaching 400,171 km from Earth’s surface. The mission was redirected after an oxygen tank explosion, using the Moon’s gravity to return to Earth. The record is unlikely to be surpassed before 2020, when the US and Japan plan to return to the […]
Low Earth Orbit (LEO) is between 124-1240 miles above Earth, while Medium Earth Orbit (MEO) is from 1243 miles to geostationary orbit (GSO) at 22,236 miles. Satellites in GSO orbit once a day and are synchronized with Earth’s rotation. Proposed space hotels are in LEO, while solar-powered satellites are in GSO for continuous sunlight. Low […]
Fuller’s Earth, a blend of aluminum, iron, magnesium, and silica, is commonly used for its absorbent properties. Alternatives include attapulgite, bentonite, and calcium montmorillonate. Industries use it for filtration, personal care products, and in the film industry. Clay has been used for medicinal purposes and contains minerals such as calcium, magnesium, and potassium. It also […]
Theia, a Mars-sized body that formed over 4 billion years ago, collided with Earth, creating a volume of molten rock that formed the Moon. The largest asteroid to hit Earth was about 6 miles in size, with the largest verified crater being Vredefort in South Africa. The Wilkes Land anomaly in Antarctica may indicate an […]
The Moon’s “dark side” is actually the “far side” and gets cycles of day and night. Tidal locking, caused by gravitational pull and friction, explains why the same side always faces Earth. The Moon’s rotation has slowed to match the tidal bulge, creating an equilibrium. The Earth’s rotation also slows, but to be perfectly synchronized […]
The International Space Station (ISS) orbits the Earth at an altitude of about 220 miles, but this distance can change due to atmospheric drag, solar activity, and space junk. LEO is preferred for manned space stations, but objects in this region must have their orbits adjusted from time to time. At an altitude of 220 […]
Rare earth elements include 15 lanthanides and 2 transition metals, important to modern technology, found in economically exploitable mineral deposits. Mining and processing can be expensive and lead to radioactive waste. Cerium is the most common and used to reduce carbon monoxide emissions. There are 17 different rare earth elements, including 15 lanthanides and two […]
The US Space Surveillance Network has tracked every object in orbit over 10 cm since 1957. There are approximately 3,000 satellites in orbit, with the largest being the International Space Station. The operational lifetime of satellites is 5-20 years, and many countries and international companies have launched them for military and commercial purposes. The SSN […]
In 1977, astronomer Jerry R. Ehman discovered a strong signal from space that lasted over a minute, detected by the Ohio State Radio Telescope. Dubbed the “WOW!” signal, it likely had an intelligent origin. The SETI Institute continues to collect data from its point of origin. World leaders and many Americans have reported UFO sightings. […]
Carbon-graphene airgel is the lightest material in the world, weighing 0.16 milligrams per cubic centimeter and capable of absorbing up to 900 times its own weight. It could be used to clean up oil spills. Aerogels have been used by NASA to protect space equipment and were first used commercially as a thickening agent for […]
Asteroid Florence will pass close to Earth on Sept. 1 at a safe distance of 4.4 million miles. It will be visible to enthusiasts in small telescopes and won’t get that close again until about the year 2500. It is the largest asteroid to pass this close since NASA’s program began. Now that you’ve recovered […]
Black holes are objects in space with strong gravity that can trap light and matter. They come in different sizes, including massive ones at the center of galaxies. There may be hundreds of black holes in the Milky Way, with wind speeds that can exceed 20 million miles per hour. A black hole is an […]
Around 50,000 tons of debris enter Earth’s atmosphere each year, but most disintegrate before impact. NASA predicts a large asteroid impact every 100 years, with most being small and causing no damage. The largest asteroid is Ceres, and asteroids may be leftover material from the solar system’s formation. 10 spacecraft have orbited or landed on […]
The Oligocene epoch of the Paleogene period and Cenozoic era saw the beginning of a cooling trend, with glaciers forming over Antarctica and forests contracting closer to the equator. Sea levels were higher, and grasses began to dominate over forests, leading to the evolution of four-chambered stomachs in animals. The period saw the evolution of […]
