Exploring Asteroids: Japan's Bold Mission to Fire a Bullet
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Chapter 1: Introduction to Hayabusa-2
Approximately 180 million miles from our planet, there exists a small asteroid named Ryugu, which measures about 0.6 miles in diameter and completes its orbit around the sun approximately every 16 months. If all goes according to plan, today marks the day we will shoot a bullet directly into this celestial body, all for the sake of scientific investigation.
Scientists have been gearing up for this ambitious endeavor for nearly a decade. In 2014, Japan's space agency, JAXA, launched Hayabusa-2, a robotic spacecraft specifically designed to explore Ryugu closely and enhance our understanding of the structure and makeup of asteroids in our solar system. The spacecraft successfully arrived at Ryugu in June, maintaining synchronization with the asteroid's solar orbit.
This mission is undoubtedly one of the most audacious undertakings ever attempted by space scientists and engineers. Hayabusa-2 is equipped with a variety of instruments that capture images and data across multiple spectra. A significant objective is to deploy four different rovers, three of which landed on the asteroid's surface last fall, offering the first glimpse of a remarkably vibrant terrain.
Section 1.1: Sample Collection Strategy
One of the most daring aspects of this mission involves the sample collection process. On Thursday, February 21, 2019, the spacecraft will descend toward Ryugu's surface and make contact using a sampling horn. Upon contact, it will fire a 5-gram metallic bullet into the asteroid at speeds exceeding 670 miles per hour. The horn's catcher will gather as much of the expelled debris as possible, aided by the asteroid's microgravity environment. Following this initial collection, Hayabusa-2 will perform a second shot to capture additional material. The ultimate aim is to retrieve authentic samples of the asteroid to bring back to Earth for further laboratory analysis.
This video titled "Anti-Tank Round vs Asteroid - For Science! - Hayabusa 2" dives deeper into the scientific rationale behind this unique approach and the excitement surrounding it.
Subsection 1.1.1: The Need for Explosives
But that's not all: A second sample return effort is planned for later in the spring, which will involve detonating explosives to carve a six-foot crater into Ryugu's surface, allowing for the collection of subsurface materials.
Why such extreme measures? While some researchers hope that analyzing these rocks may provide insights into future asteroid resource prospecting, the primary focus for most scientists is to use the Ryugu samples to gain a deeper understanding of the solar system's origins. Together with the OSIRIS-REx mission, which also targets a near-Earth asteroid for study and sample return, Hayabusa-2 presents a significant opportunity to enhance our knowledge about the early solar system and its potential role in the emergence of life on Earth.
Section 1.2: The Importance of Sample Returns
Currently, our understanding of the solar system's formation largely comes from meteorites that have struck Earth over its 4.5 billion-year history. We've gained considerable knowledge from the thorough examination of these materials, yet our insights are still constrained by factors such as contamination from atmospheric entry or surface impacts. While orbiter missions that study asteroids from afar provide valuable data, remote imaging cannot be subjected to physical or chemical analysis, limiting our knowledge about the composition and formation of these celestial bodies. This is why sample collection, regardless of its boldness, is so promising.
“What the sample return really tells us is that we know where the asteroid comes from, we have pictures of it, and we have this sample that has not been contaminated by other factors,” explains Michael Nolan, head of the OSIRIS-REx science team at the University of Arizona. An intact, pristine rock that has remained virtually untouched for billions of years offers unparalleled insights.
Chapter 2: The Significance of Ryugu Samples
JAXA's original Hayabusa mission marked the first successful sample return from a near-Earth asteroid, albeit with mixed results, as the samples collected were more akin to particles from a volcanic rock, and the mission faced numerous challenges. Nevertheless, the tiny dust grains returned from that mission contributed significantly to our understanding of the timeline and history of certain solar system rocks, particularly those found beyond the asteroid belt. Hayabusa-2 aims to advance this research further. Nolan notes that Ryugu is a more primitive rock, rich in carbon and adorned with a unique gemstone-like appearance, distinguishing it from Bennu, the focus of the OSIRIS-REx mission. “We’re going to get two very different pieces of solar system history,” Nolan emphasizes.
These samples hold the potential to reveal extensive insights into the role of asteroids in transporting organic and inorganic materials across celestial bodies. In essence, they could shed light on whether asteroid impacts contributed to the seeding of early Earth with the essential ingredients for life.
But first, the samples must be collected. Hayabusa-2 is set to conclude its mission later this year, departing from Ryugu in December and returning to Earth with its samples in 2020. Let’s hope today's attempt is successful and doesn't backfire (pun intended). The operation is scheduled for 6:00 p.m. Eastern Time on February 21, 2019, and JAXA plans to broadcast the entire event live with English translation.
In the video titled "What Happens When You Shoot An Asteroid With An 'Anti-Tank Weapon'," viewers can explore the implications and excitement surrounding this extraordinary mission.