Latest news with #GiuseppePiazzi
National Geographic
6 days ago
- Science
- National Geographic
Pluto
The world was introduced to dwarf planets in 2006, when petite Pluto was stripped of its planet status and reclassified as a dwarf planet. The International Astronomical Union (IAU) currently recognizes two other dwarf planets, Eris and Ceres. What differentiates a dwarf planet from a planet? For the most part, they are identical, but there's one key difference: A dwarf planet hasn't "cleared the neighborhood" around its orbit, which means it has not become gravitationally dominant and it shares its orbital space with other bodies of a similar size. (Astronomers and other experts are debating this definition.) Is Pluto a Dwarf Planet? Because it has not cleared the neighborhood around its orbit, Pluto is considered a dwarf planet. It orbits in a disc-like zone beyond the orbit of Neptune called the Kuiper belt, a distant region populated with frozen bodies left over from the solar system's formation. The dwarf planet is a whopping 3.7 billion miles (5.9 billion kilometers) from the sun, and its average temperature hovers around -356 degrees Fahrenheit (-215 degrees Celsius). Pluto's surface is composed of a mixture of frozen nitrogen, methane, and carbon monoxide ices. The dwarf planet also has polar caps and regions of frozen methane and nitrogen. Pluto has three known moons, Hydra, Nix, and Charon. With a diameter of about 737 miles (1,186 kilometers), Charon is the largest of Pluto's moons. The duo's gravity puts them in a synchronous orbit, which means they face each other with the same side all the time. In January 2006, NASA launched its New Horizons spacecraft. It swung past Jupiter for a gravity boost and scientific studies in February 2007, conducted a six-month-long reconnaissance flyby study of Pluto and its moons in summer 2015, and culminated with Pluto's closest approach on July 14, 2015. As part of an extended mission, the spacecraft is heading farther into the Kuiper Belt to examine another of the ancient, icy mini-worlds in that vast region, at least a billion miles beyond Neptune's orbit. New Horizons also found Pluto to have blue skies and water ice. Pluto nearly fills the frame in this black and white image from the Long Range Reconnaissance Imager (LORRI) aboard NASA's New Horizons spacecraft, taken on July 13, 2015 when the spacecraft was 476,000 miles (768,000 kilometers) from the surface. This is the last and most detailed image sent to Earth before the spacecraft's closest approach to Pluto on July 14. Photograph courtesy NASA/APL/SwRI Ceres Also considered by many to be an asteroid, Ceres, like Pluto, was also renamed as a dwarf planet in 2006. Ceres was discovered by Italian astronomer Giuseppe Piazzi in 1801. Ceres's shape resembles a flattened sphere with a diameter of about 590 miles (950 kilometers). It is by far the largest and most massive known body in the asteroid belt, and it contains about one-third of the estimated total mass of all asteroids in the belt. Ceres is made up of a rocky inner core surrounded by a mantle of water-ice. A thin, dusty, outer crust covers the dwarf planet named after the Roman goddess of grain.
News18
30-06-2025
- Science
- News18
Why is June 30 World Asteroid Day? All You Need to Know and 10 Key Facts
Last Updated: International Asteroid Day is observed to help people understand how dangerous it could be if an asteroid ever hit the Earth. World Asteroid Day 2025: Asteroids are strange space rocks that move around the sun. They aren't planets or comets; they are made of metal, rock, or ice. Some are tiny, like rubble, while others are huge, almost the size of small planets. They don't have any atmosphere, but they can still be very dangerous. If one crashes into Earth, it can cause a lot of harm. That's why it's important to know about them. To help people understand the risks, International Asteroid Day is observed every year on June 30. The day is observed to help people understand how dangerous it could be if an asteroid ever hit the Earth. International Asteroid Day is celebrated every year on June 30. This year, it falls on a Monday. Why is June 30 World Asteroid Day? On June 30, 1908, a massive explosion happened in the sky above a remote forest in Siberia, near the Tunguska River. A giant fireball, believed to be about 50 to 100 meters wide, destroyed around 2,000 square kilometers of forest and flattened nearly 80 million trees. The blast was so powerful that people living 60 km away were knocked off their feet. Even today, the exact cause of this explosion is still a mystery. Some scientists think it was caused by a meteor or a comet, while others believe it could have been a result of a powerful cosmic event. Many also think it might have been an asteroid. Whatever the cause, the explosion released energy about 185 times stronger than the atomic bomb dropped on Hiroshima. To raise awareness about such dangers, the United Nations observes June 30 as International Asteroid Day every year. In the past decade, a few asteroids have come very close to Earth, just a few hundred thousand kilometers away. Scientists have also found proof that about 66 million years ago, a huge asteroid hit Earth and wiped out around 75 per cent of all life, including the dinosaurs. International Asteroid Day 2025: All You Need To Know In December 2016, the United Nations officially declared June 30 as International Asteroid Day. This date was chosen to mark the anniversary of the huge asteroid explosion that happened in Siberia on June 30, 1908. The idea for this day came from the Association of Space Explorers and was supported by a UN space committee. The main purpose of International Asteroid Day is to make people aware of how dangerous an asteroid impact can be. Since many people don't know much about asteroids or the risks they bring, the day is used to educate them through events, campaigns, and other activities. International Asteroid Day 2025: 10 Key Facts Asteroids come in many shapes and sizes, and studying them helps scientists learn how the solar system was formed. The first asteroid ever discovered was Ceres, found by Giuseppe Piazzi in 1801. About 65 million years ago, an asteroid hit Earth and started a series of events that led to the extinction of dinosaurs. Most asteroids orbit the Sun in a region called the asteroid belt, which lies between Mars and Jupiter. Some asteroids are the rocky leftovers of comets, after all their ice has melted away. NASA says there are over 1 million asteroids in space. These rocky objects, sometimes called small planets, usually have odd shapes, though a few are almost round. Interestingly, around 150 of them even have their own moons, and some have two! Most asteroids orbit the Sun in a region between Mars and Jupiter, known as the main asteroid belt. The largest one, called Vesta, is about 530 km wide. Asteroid Day is not just about learning what asteroids are—it's also a time to think about how we can protect Earth from a possible asteroid impact in the future. First Published: June 30, 2025, 07:20 IST
The Hindu
27-06-2025
- Science
- The Hindu
Five famous space rocks
Asteroids are small, rocky objects that orbit the Sun. They are much smaller than planets and are sometimes called minor planets or planetoids. Most asteroids are found in the asteroid belt, a region between the orbits of Mars and Jupiter. Why do we have a special day to celebrate space rocks? On June 30, 1908, a massive explosion over Tunguska in Siberia flattened approximately 2,150 of forest. This was attributed to the airburst of a small asteroid or comet. In December 2016, the UN General Assembly officially designated June 30 as International Asteroid Day to educate the public about asteroid impact hazards. Let us now look at five famous asteroids. Ceres The largest object in the asteroid belt between Mars and Jupiter, Ceres holds the distinction of being the first to be discovered, in 1801 by Giuseppe Piazzi. With a diameter of approximately 940 km, it is so massive that it is now classified as a dwarf planet. Ceres has a rocky core and a mantle of water ice. Observations suggest there may be briny water below its surface. Scientists are especially interested in Ceres because it may hold important clues about the early solar system and the origin of water on Earth. Vesta Also known as 4 Vesta, this was formed about 4.56 billion years ago, shortly after the solar system began. This makes it one of the earliest bodies to solidify from the solar nebula. Vesta's age and structure provide crucial insights into planetary formation. NASA's Dawn mission visited the asteroid in 2011 to study this remarkable relic and understand how the early solar system evolved. Eros (433 Eros) Discovered in 1898, Eros is a near-Earth asteroid (NEA) about 34km long. It was the first to be orbited and landed on by a spacecraft: NEAR Shoemaker in 2000–2001. Eros is classified as an S-type asteroid, composed primarily of silicate rock. Its elongated shape and cratered surface provide valuable information about asteroid geology. Itokawa Itokawa is a small peanut-shaped near-Earth asteroid (NEA), just 535m in length. It became famous after Japan's Hayabusa mission successfully collected samples from its surface in 2010; the first such mission in history. Itokawa is a 'rubble pile' asteroid, composed of loose rocks held together by gravity, rather than a solid monolith. 2015 TC25 The smallest known asteroid is 2015 TC25, discovered in October 2015, and measures only about two meters in diameter; roughly the size of a small car. It is an E-type asteroid, known for its bright, reflective surface, and spins incredibly fast, completing one rotation every two minutes. Despite its tiny size, it was detected using ground-based telescopes, highlighting significant advances in observational astronomy.
