Is the Moon getting farther away from Earth? – Judah, 9, Broken Arrow, Oklahoma

The Moon is getting 1½ inches (3.8 centimeters) farther away from the Earth every year.

Scientists measure the distance to the Moon by bouncing lasers off mirrors placed there by space probes and astronauts.

By measuring the amount of time it takes light to travel to the Moon and back, scientists can very precisely measure the distance to the Moon and how the distance changes.

The distance to the Moon actually changes over a single month as it goes around the Earth. The Moon is typically 239,000 miles (385,000 km) away from the Earth, but its orbit is not a perfect circle and changes by about 12,400 miles (20,000 km) as it orbits the Earth. This change is why some full moons are a bit bigger than others; these are called supermoons.

As an astrophysics researcher, I’m interested in the motion and interaction of objects such as planets, stars and galaxies. The motions of the Earth and Moon have many interesting consequences, and studying how they move over time can help researchers better understand how each has changed over the 4½ billion years since the Earth and Moon formed.

Tidal forces

So, why is the Moon getting farther away? It’s all because of tides.

Tides come from a difference in gravity across an object. The force of gravity exerted by the Moon is about 4% stronger on the side of Earth that faces toward the Moon, compared to the opposite side of the Earth facing away, because gravity gets weaker with distance.

This tidal force causes the oceans to slosh around in two bulges that point toward and away from the Moon. They do this because the gravitational force pulling on Earth by the Moon isn’t just an average force that’s the same strength everywhere. The Moon’s gravity is strongest on the closer side of the Earth, creating a bulge of water pointing toward the Moon. It’s weaker on the opposite side of the Earth, which leaves another bulge of water that lags behind the rest of the Earth.

As the Earth rotates, these bulges move around and keep pointing at the Moon because of its gravitational pull. In New York City or Los Angeles, the water level can change by about 5 feet due to these tidal bulges.

These liquid bulges do not quite line up with the Moon – they “lead” it a little bit because the Earth is rotating and dragging them forward. These bulges also exert a gravitational pull back on the Moon. The bulge closer to the Moon isn’t just pulling the Moon toward the center of the Earth, but also a little bit ahead in its orbit – like the boost a sports car gets as it goes around a curve.

This forward pull from the closer tidal bulge causes the Moon to speed up, which causes the size of its orbit to increase. Think of a baseball player hitting a home run. If the player hits the ball faster at home plate, it’ll zoom higher up into the sky.

So the bottom line is that the gravity of the closer tidal bulge on the Earth is pulling the Moon forward, which increases the size of the Moon’s orbit. This means that the Moon gets slightly farther away from the Earth. This effect is very gradual and only detectable on average over years.

Does the Moon’s increasing distance affect Earth?

The Moon gains momentum as its orbit gets bigger. Think about spinning a weight attached to a string. The longer the string, the more momentum the weight has, and the harder it is to stop.

Because the Earth is doing the work of increasing the Moon’s momentum, the Earth’s rotation slows down in turn, as its momentum goes to the Moon. To put it another way, as the Moon’s orbital momentum increases, the Earth’s rotational momentum decreases in exchange. This exchange makes a day get very slightly longer.

But don’t worry, these effects are so small: 1.5 inches per year compared to a distance of 239,000 miles (384,000 km) is just 0.00000001% per year. We’ll keep having eclipses, tides and days that last 24 hours for millions of years.

Was the Moon closer to us in the past?

The Earth’s days were shorter in the past.

The Moon probably formed around 4.5 billion years ago, when a young Earth was hit by a Mars-size protoplanet, causing a lot of material to get knocked off into space.

Eventually, that material formed the Moon, and it was initially much closer to the Earth. Back then, you’d see the Moon much bigger in the sky.

By examining fossilized clam shells for material showing their daily growth patterns, paleontologists found evidence that 70 million years ago – near the end of the time of dinosaurs – the day was only 23.5 hours long, just as predicted by astronomical data.

What will happen in the future?

So, will the Moon eventually escape from the Earth’s gravitational pull as it moves away?

If we fast-forward tens of billions of years into the future, eventually the Earth’s rotation could slow down until it is tidally locked with the Moon. That means that it would take just as long for the Earth to rotate as the Moon does to orbit. At this point, the Moon would stop getting more distant, and you would see the Moon only from one side of the Earth.

But two things will stop that from happening. First, in a billion years or so, the Sun will get brighter and boil away the oceans. Then, there won’t be large tidal bulges of water to cause the Moon to get more distant. A few billion years later, the Sun will expand into a red giant, probably destroying the Earth and the Moon.

But these events are so far in the future that you don’t need to worry about them. You just get to enjoy tides on the beach, solar eclipses and our beautiful Moon.

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Stephen DiKerby, Postdoctoral Researcher in Physics and Astronomy, Michigan State University

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

Fossil fuels still power much of the world, even though renewable energy has become cheaper in most places and avoids both pollution and the climate damage caused by burning coal, oil and natural gas.

To understand this paradox, it helps to look at how countries – particularly major greenhouse gas emitters, including the U.S., China and European nations – are balancing the pressures of rising electricity demand with the global need to reduce greenhouse gas emissions that are warming the planet.

US embraces fossil fuels

The United States makes no secret of its fossil fuel ambitions. It has a wealth of fossil fuel reserves and a politically powerful oil and gas industry.

Since President Donald Trump took office in January 2025, his administration has been promoting oil and gas drilling and coal production, pointing to rising electricity demand to justify its moves, particularly to power artificial intelligence data centers.

Reviving the “drill, baby, drill” mantra, the Trump administration has now embraced a “mine, baby, mine” agenda to try to revive U.S. coal production, which fell dramatically over the past two decades as cheaper natural gas and renewable energy rose.

The Department of Interior on Sept. 29 rolled out a plan to “unleash American coal power” by opening 13 million acres of federal land to mining. The Department of Energy also pledged US$625 million to try to make coal competitive. It includes lowering the royalty rates mining companies pay and extending the operating lifespans of coal-fired power plants.

However, these initiatives further lock communities with coal plants into a carbon-intensive fossil fuel. Coal’s resurgence would also have public health costs. Its pollution is linked to respiratory illness, heart disease and thousands of premature deaths each year from 1999 to 2020 in the United States.

The Trump administration is also ceding the clean energy technology race to China. The administration is ending many renewable energy tax credits and pulling federal support for energy research projects.

I work in the Climate Policy Lab at The Fletcher School of Tufts University, where we maintain a suite of databases for analyzing countries’ energy research budgets. The Trump administration’s 2026 U.S. budget request would slash funding for energy research, development and demonstration to $2.9 billion — just over half the budget allocated in 2025. These energy research investments would fall to levels not seen since the mid-1980s or early 2000s, even when accounting for inflation.

China’s clean energy push – and coal expansion

While the United States is cutting renewable energy funding, China is doubling down on clean energy technologies. Its large government subsidies and manufacturing capacity have helped China dominate global solar panel production and supply chains for wind turbines, batteries and electric vehicles.

Cheaper Chinese-manufactured clean energy technologies have enabled many emerging economies, such as Brazil and South Africa, to reduce fossil fuel use in their power grids. Brazil surged into the global top five for solar generation in 2024, producing 75 terawatt-hours (TWh) of electricity and surpassing Germany’s 71 TWh.

The International Energy Agency now expects global renewable energy capacity to double by 2030, even with a sharp drop expected in U.S. renewable energy growth.

However, while China expands clean energy access around the world, its production and emissions from coal continue to rise: In the first half of 2025, China commissioned 21 gigawatts (GW) of new coal power plants, with projections of over 80 GW for the full year. This would be the largest surge in new coal power capacity in a decade for China. Although China pledged to phase down its coal use between 2026 to 2030, rising energy demand may make the plan difficult to realize.

China’s paradox — leading in clean energy innovations while expanding coal — reflects the tension between ensuring energy security and reducing emissions and climate impact.

Europe’s scramble for reliable energy sources

The European Union is pursuing strategies to reduce its reliance on fossil fuels amid the ongoing geopolitical tensions with Russia.

Russia’s invasion of Ukraine exposed many countries to supply disruptions and geopolitical turmoil, and it triggered a global energy crisis as countries once reliant on Russian oil and gas scrambled to find alternatives.

In June 2025, the European Commission proposed a regulation to phase out Russian fossil fuel imports by the end of 2027, aiming to enhance energy security and stabilize prices. This initiative is part of the broader REPowerEU plan. The plan focuses on increasing clean energy production, improving energy efficiency and diversifying oil and gas supplies away from Russia.

Renewables are now the leading source of electric power in the EU, though natural gas and oil still account for more than half of Europe’s total energy supply.

The EU’s fossil energy phaseout plan also faces challenges. Slovakia and Hungary have expressed resistance to the proposed phaseout, citing concerns over energy affordability and the need for alternative supply sources. Hungarian Prime Minister Victor Orbán said Hungary would continue importing Russian oil and gas. Cutting off these supplies, he asserted, would be an economic “disaster” and immediately reduce Hungary’s economic output by 4%.

The path to reducing Europe’s dependence on fossil fuels thus involves navigating internal disagreements and incentivizing long-run sustainable development. Europe does appear to be gaining in one way from the U.S. pullback from clean energy. Global investment in renewable energy, which hit a record high in the first half of 2025, increased in the EU as it fell in the U.S., according to BloombergNEF’s analysis.

Brazil: Torn on fossil fuels as it hosts climate talks

In November 2025, representatives from countries around the world will gather in Brazil for the annual United Nations climate conference, COP30. The meeting marks three decades of international climate negotiations and a decade since nations signed the Paris Agreement to limit global temperature rise.

The conference’s setting in Belém, a city in the Amazon rainforest, reflects both the stakes and contradictions of climate commitments: a vital ecosystem at risk of collapse as the planet warms, in a nation that pledges climate leadership while expanding oil and gas production and exploring for oil in the Foz do Amazonas region, the mouth of the Amazon River.

Thirty years into global climate talks, the disconnect between promises and practices has never been so clear. The world is not on track to meet the Paris temperature goals, and the persistence of fossil fuels is a major reason why.

Negotiators are expected to debate measures to curb methane emissions and support the transition from fossil fuels. But whether the discussions can eventually translate into a concrete global phaseout plan remains to be seen. Without credible plans to actually reduce fossil fuel dependence, the annual climate talks risk becoming another point of geopolitical tension.

Kate Hua-Ke Chi, Doctoral Fellow, The Fletcher School, Tufts University

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