Comets may have been responsible for the presence of water on Earth, scientists have claimed, according to a new research published this week in Science Advances. The researchers focused on Comet 67P/Churyumov-Gerasimenko and discovered that the molecular structure of water found on the celestial body closely resembled that of Earth’s oceans. While water existed in the gas and dust form when Earth formed around 4.6 billion years ago, questions regarding how it ultimately became rich in liquid water have puzzled scientists.

Researchers are of the view that a substantial portion of our oceans came from the ice and minerals on asteroids and possibly comets that crashed into Earth. To further their theory, the researchers led by Kathleen Mandt, a planetary scientist at NASA’s Goddard Space Flight Center, decided to use an advanced statistical computation technique to find the molecular structure of water on 67P which belongs to the Jupiter family of comets, using data captured by European Space Agency’s (ESA) Rosetta mission to the asteroid.

Also Read | Mysterious ‘Dark Comets’ May Pose Bigger Threat Than Previously Thought To Earth

Earth’s specific signature

The water on Earth has a unique molecular signature which has to do with specific rations of the hydrogen variant, or isotope, called deuterium. For the last few decades, deuterium levels in water found in the vapour trails of several Jupiter-family comets displayed similar levels to that of Earth’s water.

“So I was just curious if we could find evidence for that happening at 67P. And this is just one of those very rare cases where you propose a hypothesis and actually find it happening,” said Ms Mandt.

As it turned out, Ms Mandt’s team found a clear connection between deuterium measurements in the comet and the amount of dust around the Rosetta spacecraft.

“As a comet moves in its orbit closer to the Sun, its surface warms up, causing gas to release from the surface, including dust with bits of water ice on it. Water with deuterium sticks to dust grains more readily than regular water does,” the study highlighted.

“When the ice on these dust grains is released into the coma, this effect could make the comet appear to have more deuterium than it has,” it added.

The research has big implications not only for understanding comets’ role in delivering Earth’s water but also for understanding comet observations that provide insight into the formation of the early solar system.

A new research studying the impact of climate change on our planet has revealed a shocking discovery – earth’s axis has tilted by 31.5 inches (nearly 80 centimetres). Researchers attribute this change to pumping of Earth’s groundwater by humans, which they say can not only change the planet’s rotation but also impact sea-level rise. The study has been published in the journal Geophysical Research Letters.

The change in Earth’s tilt is equal to .24 inches of sea level rise, according to Popular Mechanics.

“Earth’s rotational pole actually changes a lot. Our study shows that among climate-related causes, the redistribution of groundwater actually has the largest impact on the drift of the rotational pole,” Ki-Weon Seo, a geophysicist at Seoul National University and study lead, said in a statement.

The authors further said that earth spins a little differently as water is moved around.

How Does Earth’s Tilt Change?

Earth’s tilt, or axial precession, is influenced by the distribution of mass (in this case water) across the planet. The melting of glaciers and polar ice sheets from Greenland and Antarctica contributes significantly to this redistribution. As ice melts, the water flows toward the equator, altering Earth’s balance and causing its axis to shift – a process akin to how a figure skater’s spin slows when their arms extend outward.

The study takes into account data from 1993 to 2010 that shows the pumping of as much as 2,150 gigatons of groundwater has caused a change in the Earth’s tilt of roughly 31.5 inches. The pumping is largely for irrigation and human use, said the study first published in 2023 and revised now.

What is groundwater?

Groundwater is water stored beneath the Earth’s surface in soil pores and rock fractures, forming part of the hydrological cycle. It originates from precipitation that infiltrates the ground, replenishing underground aquifers. These aquifers serve as critical freshwater reservoirs, supplying drinking water, irrigation for agriculture, and industrial needs.

Groundwater is often extracted through wells and springs. Its availability and quality depend on factors like recharge rates, geological formations and human activities. 

It has a variety of utilities, including farming and being used as drinking water.

Why It Matters?

Though the tilt might seem insignificant on a human scale, over geological timescales, such shifts can cause notable environmental consequences. For instance, the redistribution of water can affect sea level changes differently across regions. It also impacts the planet’s internal systems, including its magnetic field, which shields us from harmful solar radiation.

In a groundbreaking discovery, experts have identified ancient remnants of a long-lost tectonic plate, dubbed Pontus, dating back an astonishing 120 million years. This finding sheds new light on Earth’s history and underscores the ongoing quest for knowledge about our planet. According to Indy100.com, researchers Suzanna van de Lagemaat and Douwe van Hinsbergen from Utrecht University made the breakthrough by analysing geological data from the Asia-Pacific region. Their prediction has now been confirmed, revealing the existence of Pontus, a previously unknown part of Earth’s crust in Borneo. 

Geologist Suzanna van de Lagemaat said, “We thought we were dealing with relics of a lost plate that we already knew about. But our magnetic lab research on those rocks indicated that our finds were originally from much farther north, and had to be remnants of a different, previously unknown plate.”

She continued, ”But our magnetic lab research on those rocks indicated that our finds were originally from much farther north, and had to be remnants of a different, previously unknown plate.”

Press release!@Suzannavdl‘s PhD research yielded a nice surprise: the reconstruction of the Pontus Plate that we predicted 11 years ago based on tomography. And now it rolled out of her reconstruction .https://t.co/rNUOM8oazK@UUGeo@UUEarthSciencespic.twitter.com/3hXVeSx334

— Douwe van Hinsbergen (@vanHinsbergen) October 9, 2023

Researchers reconstructed the ancient Pontus plate, estimating it covered an area roughly one-quarter the size of the Pacific Ocean. Formed during the supercontinent Pangaea, Pontus lay beneath the vast ocean separating Eurasia and Australia 160 million years ago. As Pangaea broke apart, the Pontus plate was gradually subducted or swallowed by neighbouring plates. This geological process carried countries like the Philippines and Borneo to their present-day locations.

Notably, van de Lagemaat focussed her research on the intricate Junction Region, where tectonic plates converge between Japan, Borneo, the Philippines, New Guinea, and New Zealand. Her groundbreaking research enabled the creation of a stunning visual reconstruction.

This 3D clip revealed 160 million years of tectonic plate movements, from the dinosaur era to the present day. 

New Delhi:

The Earth will embrace a new and temporary ‘mini moon’ tonight, with a connection to India’s epic Mahabharat. Called “2024 PT5” it is just about ten meters in diameter and it will remain in the Earth’s orbit for about 53 days before heading back into the vastness of the solar system.

Its size, though, makes it way too small to register — the diameter of the Moon is 3,476 kilometres.  The “2024 PT5” is 350,000 times smaller and will not be visible to the naked eye. But special telescopes could well detect it well after 1.30 am.

Any naturally orbiting body around a planet is called a moon.
Planet Saturn has 146 known moons and Jupiter has 95. Mars has two moons and the Earth has just one Moon. Venus has no known moons.
Experts at ISRO monitoring “2024 PT5” said it “would not collide with Earth”.

Carlos de la Fuente Marcos and Raúl de la Fuente Marcos — the two scientists who reported it — said “Near-Earth Objects (NEOs) that follow horseshoe paths, and approach our planet at close range and low relative velocity, may undergo mini-moon events in which their geocentric energy becomes negative for hours, days or months, but without completing one revolution around Earth”.

“The object is too small and dim for typical amateur telescopes and binoculars. However, the object is well within the brightness range of typical telescopes used by professional astronomers,” Mr Marcos said to US-based website space.com.

“A telescope with a diameter of at least 30 inches, plus a CCD or CMOS detector is needed to observe this object,” he added.

The “2024 PT 5” was discovered on August 7, 2024 by the Asteroid Terrestrial-impact Last Alert System (ATLAS), an automated system funded by NASA and run from Hawaii. It is used to monitor near-earth asteroids.

The Indian space agency ISRO’s sharp lookout  — the Network for Space Objects Tracking and Analysis (NETRA) — is keeping an eye on the asteroid, which will disappear by November 25, 2024.

Mr Marcos said this is not the first time mini moons appear around the Earth. It happened in 1997, 2013 and 2018.  

“Such orbital elements are consistent with those of the Arjunas, a sparsely resonant population of small NEOs,” he added.

The “Arjuna” scientists refer to is a unique group asteroids. The other group of asteroids in the solar system are Apollo, Atira, Amor, and Aten.

The “2024 PT5” is supposed to have its origins in the Arjuna group and is expected to have a periodicity of a year.  

A prolific discoverer of asteroids and comets, Astronomer Robert H McNaught, on November 1, 1991, discovered an asteroid – later named “1991 VG” at the Siding Spring Observatory in Australia.

The name “Arjuna” was chosen by the discoverer, Mr McNaught, inspired by the Arjuna, a hero of the epic Mahabharata.
In mythology, Arjuna is known for his bravery, archery skills, wisdom and spiritual growth.

The name reflects the asteroid’s, swift passage through the solar system (like Arjuna’s swift arrows); unpredictable nature (like Arjuna’s complex character).

The International Astronomical Union (IAU) officially approved the name for the asteroid.

Dr Anil Kumar, head of ISRO’s Network for Space Objects Tracking and Analysis (NETRA), confirmed the “2024 PT5” is part of the Arjuna Asteroid grouping.

Asteroid collisions with Earth are surprisingly common, with NASA estimating 48.5 tonnes of meteoric material entering our atmosphere daily. Most burn up, producing shooting stars. Although devastating asteroid impacts are rare in Earth’s history, humanity has learned a crucial lesson from the catastrophic event 66 million years ago. The asteroid responsible for the dinosaurs’ extinction was approximately six miles wide, but significantly smaller objects still pose a significant threat. In the face of potentially catastrophic asteroid impacts, scientists are racing to develop innovative solutions to protect our planet. 

In New Mexico, scientists are exploring a futuristic solution to defend Earth against asteroid threats: harnessing X-ray blasts from nuclear explosions, the Guardian reported. Scientists at Sandia National Laboratories in Albuquerque have successfully demonstrated a revolutionary method to deflect incoming asteroids using nuclear explosions. For the experiment, researchers harnessed the power of X-rays from a nuclear blast to vaporise the surface of a nearby asteroid.

The process works by unleashing an immense pulse of radiation, heating the asteroid’s surface to tens of thousands of degrees. This creates a rapidly expanding ball of gas that can nudge the asteroid off its catastrophic course. By precisely calculating the blast’s impact, scientists believe this technique can effectively push threatening asteroids away from Earth, potentially saving humanity from doomsday. 

“The primary mechanism involves using X-rays to rapidly heat the target surface, causing it to vaporize and expand into the adjacent vacuum. The expanding gas pushes against the asteroid, transferring momentum (in the opposite direction),” authors of the study published Monday in the journal Nature Physics wrote. 

Scientists noted that the nuclear option is for larger asteroids, particularly when time is short. Researchers believe this strategy can effectively deflect asteroids up to 2.5 miles wide, although this isn’t a rigid limit.

“If there is enough warning time, one can certainly deflect larger asteroids,”  Dr Nathan Moore, the first author of the study said. 

Mr Moore and his team plan to conduct further experimental tests to refine the X-ray deflection technique, building on their initial success. Their goal is to enhance the method’s effectiveness through additional laboratory experiments. Ultimately, they envision a space-based demonstration, similar to NASA’s DART (Double Asteroid Redirection Test) mission, to test the technique on a real asteroid. 

Officials at NASA confirmed today that a 120-foot asteroid, roughly the size of a small aeroplane, will make a close approach to Earth. But do not worry, as despite close proximity, the asteroid 2022 SW3 poses no threat. NASA’s Jet Propulsion Laboratory assured there was no cause for concern when it said that the asteroid “is going to come no closer than about 1.6 million miles.”

It will pass within the distance of three times that of Earth to the Moon. Although close, the scientists are swift to say that it does not threaten Earth yet. This close encounter will be an opportunity for scientists to acquire much-needed data about near-earth objects (NEOs).

The scientists track the orbits of the known asteroids, including 2022 SW3, which periodically come close to the Earth orbit. These observations are very important for the purpose of prediction and assessing danger.

Indeed, asteroids were part of the material leftovers of the old solar system, born about 4.6 billion years ago. They don’t have atmospheres and are not shaped as planets. High technology and observation can trace their paths to the smallest detail.

A few had major implications for Earth, including the one at Chicxulub that caused the demise of the dinosaurs 66 million years ago.

Examples include NASA’s OSIRIS-REx and Japan’s Hayabusa2. Samples obtained from missions like these have been instrumental in giving answers about the origin of our solar system and how life-preserving compounds could have landed on Earth. Every asteroid that passes adds to our chances of getting ready for other potential threats.

Today’s close flyby also becomes an eye-opener to the fact that one cannot just understand asteroids or close observations of them once and for all. Though this event is not hazardous, it will be a good time to collect data in preparation for upcoming encounters by scientists.

The space agency NASA has created a defence system to ward off the fear of these near-earth objects. According to NASA, the Double Asteroid Redirection Test (DART), the world’s first planetary defence technology demonstration, successfully impacted its asteroid target in the past in an attempt to move an asteroid in space.

Earth has had a long history, but millions of years ago, the planet even had Saturn-like ring of debris around it. Surprised? A new study by Andy Tomkins and his colleagues at Monash University in Melbourne has suggested that the rings lasted for tens of millions of years, and may have affected the planet’s climate. The study is based on the assessment of 21 asteroid craters from the ‘Ordovician impact spike’ period 466 million years ago. The researchers said these crater sites were caused by larger objects in a previously unidentified ring being pulled out of orbit and crashing into Earth.

The study has been published in Earth and Planetary Science Letters. The team noticed the asteroids that the craters were located in a narrow band of land close to the equator.

Asteroids normally strike at random locations, but looking at this pattern, researchers feel that it happened after Earth’s close encounter with a large asteroid millions of years ago.

They have theorised in the study that the asteroid broke apart due to tidal forces and formed a debris ring around our planet, similar to the rings seen around Saturn.

“Over millions of years, material from this ring gradually fell to Earth, creating the spike in meteorite impacts observed in the geological record,” Mr Tomkins was quoted as saying by The Independent.

“We also see that layers in sedimentary rocks from this period contain extraordinary amounts of meteorite debris,” he explained.

But how did the craters emerge so close to the equator? Mr Tomkins and his team point to the movement of continents due to plate tectonics. They say at that time, all the sites would have been located close to the equator.

The team also relied on previous research having identified a consistent meteorite signature in a number of limestone deposits, also from that time and also once close to the equator.

The rings of Saturn are some of the most famous and spectacular objects in the Solar System. Earth may once have had something similar.

When a small body (like an asteroid) passes close to a large body (like a planet), it gets stretched by gravity. If it gets close enough (inside a distance called the Roche limit), the small body will break apart into lots of tiny pieces and a small number of bigger pieces.

All those fragments will be jostled around and gradually evolve into a debris ring orbiting the equator of the larger body. Over time, the material in the ring will fall down to the larger body, where the larger pieces will form impact craters. These craters will be located close to the equator.

So if Earth destroyed and captured a passing asteroid around 466 million years ago, it would explain the anomalous locations of the impact craters, the meteorite debris in sedimentary rocks, craters and tsunamis, and the meteorites’ relatively brief exposure to space radiation.

A giant sunshade?

Back then, the continents were in different positions due to continental drift. Much of North America, Europe and Australia were close to the equator, whereas Africa and South America were at higher southern latitudes.

The ring would have been around the equator. And since Earth’s axis is tilted relative to its orbit around the Sun, the ring would have shaded parts of Earth’s surface.

This shading in turn might have caused global cooling, as less sunlight reached the planet’s surface.

This brings us to another interesting puzzle. Around 465 million years ago, our planet began cooling dramatically. By 445 million years ago it was in the Hirnantian Ice Age, the coldest period in the past half a billion years.

Was a ring-shading Earth responsible for this extreme cooling? The next step in our scientific sleuthing is to make mathematical models of how asteroids break up and disperse, and how the resulting ring evolves over time. This will set the scene for climate modelling that explores how much cooling could be imposed by such a ring.

Andrew Tomkins, Geologist, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

NASA has shared a captivating image of the Earth’s terminator, the thin line separating day and night.

The picture, taken from the International Space Station (ISS) orbiting 267 miles above the Pacific Ocean, shows the breathtaking moment when a new day dawns on our planet.

The ISS, which completes 16 orbits of the Earth in 24 hours, offers a unique vantage point to witness the terminator, a phenomenon that occurs when the sun’s rays illuminate the Earth’s atmosphere, creating a distinct boundary between night and day. This boundary is visible as a thin, glowing line on the horizon, where the blue of the atmosphere meets the golden hues of sunrise.

Understanding the Earth’s terminator

The Earth’s terminator is the moving line that separates day and night on our planet, as per NASA. It is a result of the Earth’s rotation and its position relative to the Sun. It passes through most locations on Earth twice a day, once for sunrise and once for sunset, except for areas near the North and South Poles which experience long periods of darkness or sunlight during winter or summer months.

How Earth’s terminator affects/changes seasons

The Earth’s axis is tilted at 23.5 degrees, which causes the Northern and Southern Hemispheres to receive varying amounts of sunlight throughout the year. This tilt leads to the changing of the seasons, NASA says.

During the equinoxes (March and September), the Earth’s axis is perpendicular to its orbit, and the terminator is straight. Both hemispheres receive equal amounts of sunlight, resulting in milder temperatures and moderate weather.

The solstices (June and December) occur when the Earth’s tilt is most pronounced, and the terminator is curved. One hemisphere receives more daylight than the other, resulting in the longest and shortest days of the year.

The Earth’s tilt also affects the distribution of sunlight, impacting the length of days and nights. As the terminator moves, it alters the environment and influences natural processes.

The March equinox typically occurs around March 20/21, and the September equinox around September 22/23. The June solstice occurs around June 20/21, and the December solstice around December 21/22. These dates can vary slightly due to the Earth’s elliptical orbit and the gravitational pull of other celestial bodies.

Bengaluru:

A powerful solar storm impacted Earth in early May 2024, triggered by the highly active region AR13664 in the Sun, ISRO said on Tuesday.

This region unleashed a series of X-class flares and Coronal Mass Ejections (CMEs) directed at Earth.

According to ISRO, the resulting geomagnetic storm was the most intense since 2003, causing disruptions to communication and GPS systems.

“This is the biggest geomagnetic storm since 2003 in terms of its strength, as the flaring region on the Sun was as big as the historically important Carrington event that took place in 1859,” ISRO said in a statement.

Multiple X-class flares and CMEs have hit the Earth in the past few days, the space agency said.

“This (CME) had severe effects over high latitudes where trans-polar flights are already being reported to get diverted. More events are expected in the next few days,” ISRO noted.

The space agency said that the Indian sector got less affected as the main event of the storm happened in the early morning of May 11, when the ionosphere had not developed fully.

Also, being at lower latitudes, widespread outages haven’t been reported in India.

The Ionosphere was very turbulent over the Pacific and American sectors, ISRO said.

The Ionosphere is part of the Earth’s upper atmosphere, between 80 and about 600 km where extreme ultraviolet and x-ray solar radiation ionises the atoms and molecules, thus creating a layer of electrons.

The ionosphere is important because it reflects and modifies radio waves used for communication and navigation.

The main punch of this event so far arrived in the early morning hours of May 11 in India, when the Ionosphere was not fully developed, ISRO said.

ISRO said it has mobilised all its observation platforms and systems to record the signatures of this event. Both Aditya-L1 and Chandrayaan-2 have made observations and signatures have been analysed.

“The ASPEX payload on-board Aditya-L1 is showing high speed solar wind, high temperature solar wind plasma and energetic ion flux till now,” the space agency said. PTI GMS ANE

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)