Mars and Jupiter Get Chummy in the Night Sky. The Planets Won’t Get This Close Again until 2033

 This combination image, created from two photos provided by NASA, shows Jupiter pictured on April 3, 2017, left, and Mars pictured on Aug. 26, 2003, right. (NASA via AP)
This combination image, created from two photos provided by NASA, shows Jupiter pictured on April 3, 2017, left, and Mars pictured on Aug. 26, 2003, right. (NASA via AP)
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Mars and Jupiter Get Chummy in the Night Sky. The Planets Won’t Get This Close Again until 2033

 This combination image, created from two photos provided by NASA, shows Jupiter pictured on April 3, 2017, left, and Mars pictured on Aug. 26, 2003, right. (NASA via AP)
This combination image, created from two photos provided by NASA, shows Jupiter pictured on April 3, 2017, left, and Mars pictured on Aug. 26, 2003, right. (NASA via AP)

Mars and Jupiter are cozying up in the night sky for their closest rendezvous this decade.

They’ll be so close Wednesday, at least from our perspective, that just a sliver of moon could fit between them. In reality, our solar system’s biggest planet and its dimmer, reddish neighbor will be more than 350 million miles (575 million kilometers) apart in their respective orbits.

The two planets will reach their minimum separation — one-third of 1 degree or about one-third the width of the moon — during daylight hours Wednesday in most of the Americas, Europe and Africa. But they won’t appear that much different hours or even a day earlier when the sky is dark, said Jon Giorgini of NASA’s Jet Propulsion Laboratory in California.

The best views will be in the eastern sky, toward constellation Taurus, before daybreak. Known as planetary conjunctions, these comic pairings happen only every three years or so.

"Such events are mostly items of curiosity and beauty for those watching the sky, wondering what the two bright objects so close together might be," he said in an email. "The science is in the ability to accurately predict the events years in advance."

Their orbits haven’t brought them this close together, one behind the other, since 2018. And it won’t happen again until 2033, when they’ll get even chummier.

The closest in the past 1,000 years was in 1761, when Mars and Jupiter appeared to the naked eye as a single bright object, according to Giorgini. Looking ahead, the year 2348 will be almost as close.

This latest link up of Mars and Jupiter coincides with the Perseid meteor shower, one of the year's brightest showers. No binoculars or telescopes are needed.



What Is Japan’s Nankai Trough Megaquake Advisory?

 Japan's earthquake experts panel chief Naoshi Hirata talks about probability of megaquake on the Nankai Trough; in Tokyo, Japan, 08 August 2024 (issued 09 August 2024) after a magnitude 7.1 earthquake hit southwestern Japan on the day. (EPA/JIJI Press)
Japan's earthquake experts panel chief Naoshi Hirata talks about probability of megaquake on the Nankai Trough; in Tokyo, Japan, 08 August 2024 (issued 09 August 2024) after a magnitude 7.1 earthquake hit southwestern Japan on the day. (EPA/JIJI Press)
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What Is Japan’s Nankai Trough Megaquake Advisory?

 Japan's earthquake experts panel chief Naoshi Hirata talks about probability of megaquake on the Nankai Trough; in Tokyo, Japan, 08 August 2024 (issued 09 August 2024) after a magnitude 7.1 earthquake hit southwestern Japan on the day. (EPA/JIJI Press)
Japan's earthquake experts panel chief Naoshi Hirata talks about probability of megaquake on the Nankai Trough; in Tokyo, Japan, 08 August 2024 (issued 09 August 2024) after a magnitude 7.1 earthquake hit southwestern Japan on the day. (EPA/JIJI Press)

Japan issued its first-ever advisory on higher-than-usual risks of a megaquake, after a strong magnitude 7.1 quake occurred on Thursday at the edge of a tremulous seabed zone along the Pacific coast known as the Nankai Trough.

A possible Nankai Trough megaquake and tsunami disaster could kill hundreds of thousands of people and cause a trillion-dollar damage to Japan.

Here's a look at the risks of what could be the biggest natural disaster in Japan's modern history.

WHAT IS THE NEW RISK OF A MEGAQUAKE?

Japan's Nankai Trough quake advisory panel said the chance of a bigger earthquake striking after a magnitude 7 tremor was once in a few hundred cases, relatively higher than regular times. Earthquakes with a magnitude larger than 8 are considered megaquakes.

Japan estimates the next Nankai Trough megaquake could be as powerful as magnitude 9.1.

University of Tokyo professor Naoshi Hirata, who chairs the panel, said in a press conference that residents in areas that would be hit by such a disaster should review evacuation procedures and stay vigilant for a week.

Japan is one of the world's most earthquake-prone nations sitting on the Pacific "Ring of Fire" arc of volcanoes and oceanic trenches. In 2011, more than 15,000 people were killed in a magnitude 9.0 quake in northeast Japan that triggered a tsunami and triple reactor meltdowns at a nuclear power plant.

WHAT IS NANKAI TROUGH AND WHY IS IT SIGNIFICANT FOR QUAKES?

The Nankai Trough is off its southwest Pacific coast and runs for approximately 900 km (600 miles), where the Philippine Sea Plate is subducting under the Eurasian Plate and the accumulating tectonic strains could result in a megaquake roughly once in 100 to 150 years.

The Japanese government had previously predicted a 70-80% chance of a magnitude 8 to 9 earthquake happening along the Trough in the next 30 years.

The magnitude of an earthquake is related to the length of the fault on which it occurs, according to the United States Geological Survey. The largest earthquake ever recorded was a magnitude 9.5 on May 22, 1960 in Chile on a fault that is almost 1,000 miles long.

THE POTENTIAL DAMAGE FROM NANKAI TROUGH QUAKE AND TSUNAMI

A megaquake could result in maximum measurable tremors to areas from central Shizuoka - about 150 km (93 miles) south of capital Tokyo - to southwestern Miyazaki.

Tsunami of up to 30 meters (98 feet) may reach Japan's Pacific coasts within minutes after the quake, depending on the epicenter and tidal situation.

Coupled with landslides and fire, the disaster would be expected to claim the lives of as many as 323,000 people and destroy 2.38 million buildings, forcing nearly 10 million survivors to evacuate.

Economic damage could total up to 220 trillion yen ($1.50 trillion), or more than a third of Japan's annual gross domestic product, with long-lasting impacts on infrastructure and supply chains for coastal industrial powerhouses producing cars and other key Japanese products.

PREVIOUS NANKAI TROUGH RELATED QUAKES

Nankai Trough earthquakes have been marked on Japan's historic records multiple times since 684, often with accounts of tsunamis striking coastal villages.

The most recent Nankai Trough quake happened in 1946 with magnitude 8.0 tremor and 6.9 meter tsunami, killing 1,330 people.