🌑 Friday, April 13, 2029. A 450-meter asteroid named Apophis—Egyptian for "the serpent of chaos"— will skim past Earth at just 32,000 km, closer than our own geostationary satellites. Around 2 billion people will see it with the naked eye. Now, with the US planetary defense program in budget limbo, Japan and Europe are stepping up to launch the next-generation defense mission, RAMSES, on a Japanese H3 rocket.

Apophis: The "Serpent of Chaos" Comes Calling

Discovered in 2004, asteroid 99942 Apophis was named after the ancient Egyptian deity of chaos—the cosmic serpent that opposed the sun god Ra. The name fit. For a few terrifying weeks after its discovery, calculations briefly placed Apophis at a 2.4% probability of striking Earth on April 13, 2029, the highest threat rating ever recorded on the Torino Impact Hazard Scale.

Subsequent observations have completely ruled out an impact. But the close approach is real—and it will be the closest pass by an object this large in millennia.

Apophis measures roughly 450 by 170 meters, with an elongated, peanut-like shape. If it ever hit Tokyo, the entire Kanto Plain (the most densely populated region on Earth, home to over 40 million people) would face catastrophic damage. That's why planetary defense agencies around the world have been watching this rock for two decades.

On April 13, 2029, Apophis will pass approximately 32,000 km above Earth's surface—about one-tenth the distance to the Moon, and inside the orbit of geostationary satellites at 36,000 km. It will be visible to the naked eye across Africa, Europe, and Asia. Roughly 2 billion people are expected to watch a moving point of light cross their evening sky.

Japan Joins ESA's RAMSES Mission

To study Apophis during this once-in-millennia close pass, the European Space Agency (ESA) is building a spacecraft called RAMSES (Rapid Apophis Mission for Space Safety). The ESA Ministerial Council formally approved funding in November 2025, and on February 10, 2026, ESA signed an €81.2 million ($95.3M) contract with OHB Italia to build the spacecraft.

Japan's space agency, JAXA, is now formally joining the mission with three significant contributions:

TIRI (Thermal Infrared Imager) — A high-resolution sensor that will map Apophis's surface temperature, revealing details about rock composition and internal structure.

SAP (Solar Array Paddles) — Lightweight, flexible solar panels that will power the spacecraft through years of deep-space operations.

H3 launch vehicle — The rideshare launch from Tanegashima Space Center, Japan's national heavy-lift rocket.

This is an unprecedented level of cooperation. According to Masaki Fujimoto, Director General of JAXA's Institute of Space and Astronautical Science (ISAS), "Ramses needs to happen. We have been working closely with ESA's Space Safety Programme, and this was a mission where we wanted to offer major cooperation." Contributing across all three pillars—instrument, bus components, and launch vehicle—marks a first in the history of ESA–JAXA partnership.

Why Japan? The Hayabusa Legacy

Why did ESA hand Japan such a central role? Two decades of asteroid expertise.

Japan's first asteroid sample-return mission, Hayabusa, brought home microscopic grains from asteroid Itokawa in 2010—a world first. Its successor Hayabusa2 returned 5.4 grams of pristine material from asteroid Ryugu in 2020. Analysis of those samples has been a watershed for origin-of-life research, with detection of organics, water, and amino acids that point to asteroids as possible delivery agents of life's building blocks to early Earth.

NASA achieved its own asteroid sample return with OSIRIS-REx (asteroid Bennu) in 2023, but the technical playbook for "touch-and-go asteroid sampling" was written in Japanese.

Apophis itself was, until 2024, the target of NASA's OSIRIS-APEX mission—a repurposed extension of OSIRIS-REx. But amid US federal budget uncertainty, the future of OSIRIS-APEX is now in question. Into that gap, Japan and Europe have stepped forward.

Riding Shotgun: DESTINY+ Joins the Trip

The H3 launch carries a hidden bonus. Japan's deep-space probe DESTINY+ will ride along.

DESTINY+ (Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science) was originally meant to launch on Japan's small Epsilon S rocket. Then in November 2024, an Epsilon S engine exploded during a ground test at the Noshiro Rocket Testing Center, severely damaging the facility. DESTINY+ was left without a ride.

The H3-RAMSES rideshare offered a solution. With both spacecraft launching together, DESTINY+ will perform a flyby of Apophis before RAMSES arrives—potentially returning the world's first close-up images of the asteroid from space. That data will help refine RAMSES's operational plan when it begins its rendezvous phase.

DESTINY+'s primary destination is asteroid 3200 Phaethon, the parent body of the annual Geminid meteor shower. Two flagship asteroid science missions, one launch—the dual-mission logo was unveiled by ESA Director General Josef Aschbacher and JAXA President Hiroshi Yamakawa at the 76th International Astronautical Congress (IAC 2025) in Sydney last October.

H3's Reliability Question

Of course, all of this depends on H3 actually working.

The H3 had a rocky debut. The first vehicle failed in March 2023. After five consecutive successes, vehicle No. 8 failed in December 2025, when an internal delamination in the satellite mounting adapter triggered structural collapse during fairing separation. JAXA confirmed the cause in April 2026 and now plans the No. 6 "Type 30" test flight—a stripped-down configuration with zero solid boosters—for June 10, 2026. (For our earlier coverage of the H3 No. 8 failure investigation, see H3 Rocket No. 8 Failure: JAXA Confirms Cause and Charts Path to Recovery).

RAMSES requires a reliable H3 by the launch window of April 24 to May 11, 2028. That gives JAXA roughly two years to demonstrate consistent success. The stakes are international: if the H3 cannot deliver, ESA loses its only realistic ride to Apophis on the required schedule.

DART → Hera → RAMSES: The Lineage of Planetary Defense

Humanity's first deliberate "defensive action" against an asteroid was NASA's DART mission in September 2022. A 570 kg spacecraft slammed into the small asteroid Dimorphos (the moon of binary asteroid Didymos) at 22,530 km/h, shortening its orbital period by about 32 minutes—the world's first demonstration of kinetic impactor technology for asteroid deflection.

ESA's Hera mission, launched in October 2024, will arrive at the Didymos system in November 2026 to perform the detailed forensic analysis of the DART impact—measuring the crater, debris dynamics, and orbital changes in unprecedented detail.

RAMSES is the third mission in this lineage. It inherits Hera's spacecraft architecture, but with smaller, more compact antennas and solar panels because Apophis approaches Earth more closely than Didymos does. Hera was completed in just four years, on schedule and under budget—a track record that gave ESA the confidence to commit to the same four-year timeline (formal approval 2024 → launch 2028) for RAMSES.

In addition to the main spacecraft, RAMSES will deploy two CubeSats at Apophis. One will carry a dust analyzer and low-frequency radar. The other—built by Spanish firm Emxys and named Don Quijote—will attempt to land on Apophis's surface and transmit high-resolution surface images.

The UN's "International Year of Asteroid Awareness"

The UN has designated 2029 the International Year of Asteroid Awareness and Planetary Defence. The timing coincides exactly with Apophis's flyby—a symbolic milestone for humanity's growing realization that we live in a cosmic shooting gallery and need to take it seriously.

A JAXA report to Japan's Ministry of Education, Culture, Sports, Science and Technology summarized the strategic value of joining RAMSES: providing instrument (TIRI), bus components (SAP), and launch capability (H3) marks the first comprehensive ESA–JAXA cooperation across all three pillars; raises Japan's profile in international planetary defense; and creates spillover benefits for Japanese industry, government, and academia. The report also noted that "launching from Japan will help raise public consciousness of planetary defense as a national concern."

What We'll See

On the night of Friday, April 13, 2029, observers across Asia, Europe, and Africa will watch a moving star-like point cross the sky—a 450-meter rock skimming just inside our satellite belt. From Japan, conditions permitting, Apophis should be visible as a 3rd to 4th magnitude object.

Right alongside it, a Japanese-built infrared camera mounted on a European spacecraft will be measuring how Earth's tidal forces deform Apophis—possibly triggering small "dust avalanches" on its surface that expose interior material never before seen. Earlier in the encounter, DESTINY+ will have already streamed home the first close-up images of the asteroid, helping fine-tune RAMSES's operational plan.

Whether the next close approach by an asteroid this size brings a benign flyby or a planet-threatening impact, the data gathered at Apophis in 2029 will form the foundation of humanity's first real planetary defense playbook.

In Japan, the Hayabusa missions have made asteroid science a source of national pride, and planetary defense is increasingly seen as something that concerns ordinary citizens, not just scientists.

In your country, what kind of contributions are being made to planetary defense? How does the public react to news of asteroid close approaches? Let us know in the comments below.

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