Category Exploring the Universe

What’s space weather?

Ever wondered about the weather in space? Before that, let’s think about what dictates the weather on our planet. The Sun, which is our source of energy, plays a titular role in governing the weather on Earth. And so does it create the weather in space! The activities on the Sun’s surface can lead to a type of weather in space and this is called space weather.

Space weather is dependent on activities and changes on the Sun’s surface such as coronal mass ejections (eruptions of plasma and magnetic field structures) and solar flares (sudden bursts of radiation). We are shielded from these bursts of radiation and energy by Earth’s magnetosphere, ionosphere, and atmosphere.

Impact of space weather

The Sun is some 93 million miles away from our Earth. Yet, space weather can affect us and the solar system. The electric power distribution grids, global satellite communication, and navigation systems are all susceptible to conditions in space that are impacted by the Sun.

Space weather can damage satellites, affect astronauts and even cause blackouts on Earth. Such incidents are rare but they have happened before.

CME, solar flare

When a CME reaches Earth, it leads to a geomagnetic storm. This can disrupt services, damage power grids and cause blackouts.

For instance, back in 1989, a powerful geomagnetic storm led to a major power blackout in Canada. As a result, around 6 million people were left in the dark for about 9 hours.

Solar flares can also result in disruption of services. The strongest and most intense geomagnetic storm ever recorded occurred in 1859. This was caused by a solar flare. Called the “Carrington Event and named after England’s solar astronomer Richard Carrington who observed the activity through his telescope, the geomagnetic storm caused damage, disrupting the telegraph system on Earth. It also led to the aurorae, a result of geomagnetic activity, being visible in regions such as Cuba and Hawaii.

While telegraph networks are a thing of the past, our communications system and technologies can still be impacted by space weather. Even as most of the charged particles released by the Sun get shielded away due to Earth’s magnetic field, sometimes space weather can affect us. We need to track the activities on the Sun’s surface and understand them to protect the people and systems.

Any warning regarding bad space weather can help scientists send alerts and lessen the damage caused by it. Space agencies have observatories monitoring the Sun and detecting solar storms. These help in mitigating the effect of bad space weather.

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Naming planetary objects?

On August 23, India celebrated a technological triumph when Chandrayaan-3 landed near the Moon’s South Pole at 6:04 p.m. Since then, there has been a discussion on the naming of the landing spot, which Prime Minister Narendra Modi has termed Shiv Shakti.

Do you know how are planetary objects are usually named?

International Astronomical Union             

The International Astronomical Union (IAU), founded in 1919, is responsible for assigning names to celestial bodies and surface features on them. In the IAU, there are numerous Working Groups that suggest the names of astronomical objects and features.

In 1982, the United Nations, at its ‘Fourth Conference on the Standardisation of Geographical Names held in Geneva, recognised the role of the IAU by adopting its resolution on extraterrestrial feature names.

Key rules

The IAU has set some rules for naming planetary objects. Some of the most important rules are -the names should be simple, clear, and unambiguous; there should not be duplication of names; no names having political, military or religious significance may be used, except for names of political figures prior to the 19th Century; and if a name of a person is suggested, then he/she must have been deceased for at least three years, before a proposal may be submitted.

Process of naming

When the first images of the surface of a planet or satellite are obtained, themes for naming features are chosen and names of a few important features are proposed, usually by members of the appropriate IAU Working Group. However, there is no guarantee that the name will be accepted.

Names reviewed by an IAU Working Group are submitted by the group’s chairperson to the Working Group for Planetary System Nomenclature (WGPSN). After this, the members of the WGPSN vote on the names.

The names approved by the WGPSN members are considered as official IAU nomenclature and can be used on maps and in publications. The approved names are then entered into the Gazetteer of Planetary Nomenclature, and posted on the website of IAU.

Objections

If there are any objections to the proposed names, an application has to be sent to the IAU general secretary within three months from the time the name was placed on the website. The general secretary will make a recommendation to the WGPSN Chair as to whether or not the approved name(s) should be reconsidered.

 In 1966, the Outer Space Treaty was formed by the United Nations Office for Outer Space Affairs to set rules for international space law. One of the key aspects of this treaty was that the outer space, including the moon and other celestial bodies, shall be free for exploration and use by all states without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies.

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Are Saturn’s rings actually young?

The rings of Satum have fascinated and captivated humankind for over 400 years. It was in 1610 that Italian astronomer Galileo Galilei first observed these features through a telescope, though he had no idea what they were.

While our understanding of Saturn’s rings has matured over these four centuries, the age of these rings haven’t been determined precisely yet. The assumption that the rings likely formed at the same time as Satum draws flak as the rings are sparkling clean when compared to the planet.

A new study at the University of Colorado Boulder has provided the strongest evidence so far that the rings of Saturn are remarkably young. The research, published in May in the journal Science Advances, places the age of Saturn’s rings at around 400 million years old. When we compare this with Saturn itself, which is 4.5 billion years old, the rings are really young.

Studying dust                                                                        

The researchers arrived at this number by studying dust. By studying how rapidly the layer of dust built up on Saturn’s rings, they set out to put a date on it. It was, however, not an easy process.

The Cassini spacecraft provided an opportunity by arriving at Saturn in 2004 and collecting data until it intentionally crashed into the planet’s atmosphere in 2017. The Cosmic Dust Analyzer, which was shaped a little bit like a bucket and was aboard this spacecraft, scooped up small particles as the spacecraft whizzed by.

Just 163 grains

The researchers were able to collect just 163 grains of dust that had originated from beyond Saturn’s close neighbourhood during these 13 years. This quantity. however, was enough to make their calculations, placing the age of Saturn’s rings at a little less than 400 million years.

With this, we now know approximately how old Saturn’s rings are and that they are a relatively new phenomena in cosmic terms. With a previous study suggesting that Saturn’s rings could entirely disappear in another 100 million years, questions pertaining to how these rings were initially formed and why these short-lived, dynamic rings can be seen just now still remain.

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What are the Astronomers, who helped enhance our understanding of the cosmos?

We have always been looking up, peering into the sky, trying to find answers to the many questions about the universe. Many astronomers have tried to unravel the mysteries of the universe. From believing that Earth was flat and the planets revolved around it, we have come a long way. Let’s take a look at some of history’s greatest astronomers who helped enhance our understanding of the Cosmos.

From believing that the Earth was flat and the planets revolved around it, we have come a long way.Some 2000 years ago, when it was widely believed that the world was flat, Greek mathematician and astronomer Eratosthenes (276 BC-194 BC) calculated the Earth’s circumference. In those days, the very act of coming up with scientific thoughts which were at odds with the ones in existence was not encouraged. The theory that the Earth revolved around the Sun was itself considered heretical by the religious and after a trial, Italian astronomer Galileo Galilei was kept under house arrest until his death. Polish astronomer Nicolaus Copernicus didn’t publish his magnum opus “De revolutions orbium coelestium” (On the Revolutions of the Heavenly Spheres) until he was on his deathbed. Let’s take a look at some of history’s greatest astronomers who threw new light on the cosmos.

CLAUDIUS PTOLEMY (AD 100-AD 170)

 Astronomer and mathematician Claudius Ptolemy authored several scientific teas and is noted for his Ptolemaic system. It was a geocentric (Earth-centred) model of the universe, where the sun, stars, and other planets revolved around Earth. This model was used for a long period, for over 1200 years, until the heliocentric view of the solar system was established. Although his model of the universe was wrong, his work and the scientific texts he authored helped astronomers make predictions of planetary positions and solar and lunar eclipses. “The Almagest, a comprehensive treatise on the movements of the stars and planets, was published in the 2nd Century. It is divided into 13 books. This manual served as the basic guide for Islamic and European astronomers. He also catalogued 48 constellations. 

NICOLAUS COPERNICUS (1473-1543)

 Nicolaus Copernicus changed the way scientists viewed the solar system. Back in the 16th Century, he came up with a model of the solar system where the Earth revolved around the Sun: it was the revolutionary heliocentric model. He removed Earth from the centre of the universe and replaced it with the Sun! He also didn’t believe in the Ptolemaic model of the planets travelling in circular orbits around the Earth. He also explained the retrograde motion of the planets (retrograde motion is when planets appear to move in the opposite direction of the stars). When the Polish astronomer was 70, he published his book “De Revolutions Orbium Coelestium” (“On the Revolutions of the Heavenly Spheres”), on his deathbed. It took over a century for his idea to gain credence.

GALILEO GALILEI (1564-1642)

Optical astronomy began with Galileo Galilei. Born in Italy, Galilei is credited with creating the optical telescope. In fact, what he did was improve upon the existing models. He came up with his first telescope in 1609, modelling it after the telescopes produced in other parts of Europe. But here is the catch. Those telescopes could magnify objects only three times. Galileo came up with a telescope that could magnify objects 20 times. He then pointed it towards the sky, coming up with the greatest discoveries ever. He discovered the four primary moons of Jupiter which are referred to as the Galilean moons. He also discovered the rings of Saturn. Even though the theory of Earth circling the Sun had been around since Copernicus’ time, when Galileo defended it, he was kept under house arrest till the end of his lifetime.

JOHANNES KEPLER (1571-1630)

Danish astronomer Johannes Kepler modified the Copernican view of the solar system and changed it radically. He deduced that the planets travelled in elliptical orbits, one of the most revolutionary ideas at the time, replacing Copernicus view that they travelled in circular objects. He came up with three revolutionary laws involving the motions of planets these three laws make him a towering figure in astronomy. Kepler also observed a supernova in 1604. It is now called Kepler’s Nova.

EDMOND HALLEY (1656-1742)

“Halley’s comet is perhaps a term you would have heard quite often. English astronomer Edmond Halley never saw the comet named after him. Officially called 1P/Halley, Halley’s  comet  is a periodic comet that passes by the Earth once every 76 years (roughly). This famed comet will return in 2061. It was Halley’s mathematical prediction of the comet’s return that made him a towering figure among the list of astronomers. He said that the comet that appeared in 1456, 1531, 1607, and 1682 were all the same and that it would return in 1758. Halley was never around to witness this, but the world saw the comet and its return. The comet was later named in his honour. One of the earliest catalogues of the southern sky was also produced by Halley. In 1676, he sailed to the island St. Helena, South Atlantic Ocean. There he spent a year measuring the position of stars and came up with the first catalogue of the southern sky! Seen here is a painting of the astronomer. 

WILLIAM HERSCHEL (1750-1848)

Musician-tumed astronomer William Herschel started exploring the skies with his sister Caroline quite late in his career but eventually, he compiled a catalogue of 2.500 celestial objects The German astronomer discoverest the planet Uranus and several moons of other planets it was during his mid 30s that he startet looking up and exploring the cosmos In 1759. Herschel left Germany and moved to England where he started teaching music When Herschels interest in astronomy grew, rented a telescope. He then went ahead and built himself a large telescope to watch the celestial bodies. His sister Caroline assisted him until Herschel’s death and also became the first woman to discover a comet. She eventually discovered eight of them. When Herschel found a small object in the night sky, he explored further and found out that it was a planet. The Uranus was thus discovered. He was knighted by the monarch after the discovery and was appointed the court astronomer. Following this he gave up his music career and devoted himself to the skies. He found the moons of Uranus and Saturn Craters on the moon. Mars and Mimas (Saturn’s moon) are named after the astronomer.

ANNIE JUMP CANNON (1863-1941)

Known as the “census taker of the sky, American astronomer Annie Jump Cannon made stellar contributions to the field of astronomy. She classified around 3,50,000  stars manually. At a time when gender representation in astronomy was  skewed. Cannon with her impeccable contributions inspired many women to pursue astronomy. During that time, stars were classified alphabetically, from A to Q. based on their temperatures. She built a new classification system with ten categories and forever changed the way scientists classified stars by developing the Harvard system which is in use even today.

CARL SAGAN (1934-1996)

American astronomer Carl Sagan was not just a science poster boy but he was one of the most influential voices in the scientific  realm  who  made the cosmos a subject of interest for the masses. Sagan played a huge role in in the American space program. He popularised astronomy and through his talks and books motivated many to become sky watchers. He also founded the Planetary Society, a non-profit that is focussed on advancing space science and exploration. He was a professor of astronomy and space sciences and director of the Laboratory for Planetary Studies at Cornell University. His contributions include explaining the high temperatures of Venus and the seasonal changes on Mars. His book “Cosmos” is a bestseller that was also turned into a television show (hosted by Sagan) which was watched by a billion people in 60 countries. He also wrote a science fiction novel “Contact” which was adapted to the screen.

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What is the significance of Artemis Accord for India?

India’s aspirations in the outer space and acceptance of the Artemis Accords have affirmed the country’s interest in building a greater relationship with the National Aeronautics and Space Administration (NASA) and its partners. As the space community lauds India’s acceptance of the Artemis Accords, let us know more about it.

Artemis Accords

The Artemis Accords are part of the Artemis programme, which is a mega-initiative by NASA with the aim to land the first woman and first person of colour on the Moon, make new scientific discoveries, and explore more of the lunar surface. Artemis is the name of the goddess of the Moon in Greek mythology and also the twin sister of Apollo.

The Artemis Accords were established in 2020 by NASA, the U.S., and seven other founding member nations – Australia, Canada, Italy, Japan, Luxembourg, UAE, and the U.K. This June 21, India became the 27th country to sign the Artemis Accords.

The Artemis Accords are a set of non-binding guidelines designed to guide civil space exploration and use in the 21st Century. It is a NASA-led effort to return humans to the moon by 2025, with the ultimate goal of expanding space exploration to Mars and beyond.

The Artemis Accords reinforce and implement key obligations in the 1967 Outer Space Treaty (which provided the basic framework for international space law). The accords also affirm the importance of the Rescue and Return Agreement opened in 1968, which emphasises the responsibility of nations to safely return astronauts and equipment to Earth.

Besides, the accords emphasise the need to preserve historically significant human or robotics landing sites, artefacts, spacecraft, and other evidence of activity on celestial bodies.

Outer Space Treaty

The Outer Space Treaty is an international treaty binding the parties to use outer space only for peaceful purposes. The treaty was enforced on October 10, 1967, after being ratified by the U.S., then Soviet Union, the U.K.. and several other countries.

The treaty prohibits countries from placing nuclear arms or other weapons of mass destruction in orbit, on the Moon, or on other bodies in space. Also, no country can claim sovereignty over the Moon or other celestial bodies. The countries are liable for any damage caused by objects launched into space from their territory.

India and the Artemis Accords

India’s Indian Space Research Organisation (ISRO) and NASA had been working together in several lunar missions. However, the cooperation was limited to sharing knowledge. With the signing of the Accords, India and the US will share data, technology, and resources, and work together in ensuring the safety and sustainability of exploring the Moon.

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When did Voyager 2 achieve its closest approach to Jupiter?

On July 9, 1979, Voyager 2 made its closest approach to the largest planet in our solar system. Now in interstellar space. Voyager 2 altered some of our ideas about the Jovian system.

The Voyager probes are: humanity’s longest running spacecraft as they have been flying since 1977 Both Voyager 2 and Voyager 1 are now in interstellar space, and though their power sources are gradually fading, they are still operational as of now.

It might seem counter-intuitive, but Voyager 2 was the first to be launched on August 20, 1977-about two weeks before the launch of Voyager 1. Both spacecraft were equipped with an extensive array of instruments to gather data. about the outer planets and their systems, in addition to carrying a slow-scan colour TV camera capable of taking images of the planets and their moons.

Based on Mariners

The design of the Voyagers was based on the Mariners and they were even known as Mariner 11 and Mariner 12 until March 7. 1977. It was NASA administrator James Fletcher who announced that the spacecraft would be renamed Younger. The Voyagers are powered by three plutonium dioxide radioisotope thermoelectric generators (RTGS) mounted at the end of a boom (a long metal beam extending from the spacecraft and serving as a structure subsystem).

Even though Voyager 1 was launched a little later, it reached Jupiter first in 1979 as it took a trajectory that put it on a faster path. Voyager 2 began transmitting images of Jupiter from April 24, 1979 for time-lapse movies of atmospheric circulation. For the next three-and-a-half months, until August 5 of that year, the probe continued to click images and collect data. A total of 17,000 images of Jupiter and its system were sent back to the Earth.

The spectacular images of the Jovian system included those of its moons Callisto, Europa, and Ganymede. While Voyager 2 flew by Callisto and Europa at about half the distance between the Earth and its moon, it made an even closer approach to Ganymede.

Ocean worlds

The combined cameras of the two Voyager probes, in fact. covered at least four-fifths of the surfaces of Ganymede and Callisto. This enabled the mapping out of these moons to a resolution of about 5 km.

Voyager 2’s work, along with observations made before and after, also helped scientists reveal that each of these moons were indeed an ocean world.

On July 9, 1979, the probe made its closest approach to Jupiter. Voyager 2 came within 6,45,000 km from the planet’s surface, less than twice the distance between Earth and its moon. It detected many significant atmospheric changes, including a drift in the Great Red Spot in addition to changes in its shape and colours.

Voyager 2 also relayed photographs of other moons like lo and Amalthea. It even discovered a Jovian satellite, later called Adrastea, and revealed a third component to the planet’s rings. The thin rings surrounding Jupiter, as had been seen by Voyager 1 as well, were confirmed by images looking back at the giant planet as the spacecraft departed for Saturn. As the probe used the gravity assist technique, Jupiter served as a springboard for Voyager 2 to get to Saturn.

Studies all four giant planets

 Four decades after its closest approach to Jupiter, Voyager 2 successfully fired up its trajectory correction manoeuvre thrusters on July 8, 2019. These thrusters, which had themselves last been used only in November 1989 during Voyager 2’s encounter with Neptune, will be used to control the pointing of the spacecraft in interstellar space.

In those 40 years, Voyager 2 had achieved flybys of Saturn (1981), Uranus (1986), and Neptune (1989), thereby becoming the only spacecraft to study all four giant planets of the solar system at close range. Having entered interstellar space on December 10, 2018, Voyager 2 is now over 132 AU (astronomical unit-distance between Earth and the sun) away from the Earth, still relaying back data from unexplored regions deep in space.

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