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"God of Darkness" asteroid Apophis set for historic Earth flyby

In a bold extension of its mission, the spacecraft formerly known as OSIRIS-REx embarks on an unprecedented journey to explore asteroid Apophis.

This celestial body is set to make a historic flyby of Earth in 2029, an event unseen since the advent of recorded history.

The spacecraft, now renamed OSIRIS-APEX (Origins, Spectral Interpretation, Resource Identification, and Security – Apophis Explorer), leverages its successful past to venture into new cosmic territories.

The journey of OSIRIS-REx is nothing short of extraordinary. After a seven-year, 4 billion-mile expedition, it returned to Earth with a sample from asteroid Bennu.

This feat in September marked a pinnacle in space exploration. With its instruments still in excellent condition and a quarter of its fuel remaining, the decision to repurpose the spacecraft for a new mission was a natural progression.

Decision to explore asteroid Apophis

Apophis, an “S-type” asteroid composed of silicate materials and nickel-iron, starkly contrasts with the carbon-rich, “C-type” Bennu.

After considering several potential destinations, including Venus and various comets, NASA’s choice of Apophis was driven by its intriguingly close approach to Earth.

On April 13, 2029, Apophis will pass within 20,000 miles (32,000 kilometers) of Earth’s surface, closer than some satellites and potentially visible to the naked eye in the Eastern Hemisphere.

Asteroids of Apophis’ size, roughly 367 yards (340 meters) across, only come this close to Earth approximately once every 7,500 years. This rarity presents an invaluable opportunity for scientific exploration and understanding.

Asteroid Apophis Mission’s objectives

As explained by Amy Simon, the mission’s project scientist at NASA’s Goddard Space Flight Center, OSIRIS-APEX aims to study Apophis immediately after its close pass with Earth.

“OSIRIS-APEX will study Apophis immediately after such a pass, allowing us to see how its surface changes by interacting with Earth’s gravity,” said Simon.

This will allow scientists to observe any surface changes caused by Earth’s gravitational interaction with the asteroid.

Furthermore, Dani Mendoza DellaGiustina, principal investigator for OSIRIS-APEX at the University of Arizona in Tucson, highlights the significance of this close approach as a natural experiment.

“The close approach is a great natural experiment,” said DellaGiustina. “We know that tidal forces and the accumulation of rubble pile material are foundational processes that could play a role in planet formation. They could inform how we got from debris in the early solar system to full-blown planets.”

This event could provide insights into tidal forces and rubble pile accumulation, fundamental processes that may have played a role in planet formation.

Asteroid Apophis mission timeline

Apophis serves as a key subject in understanding potentially hazardous asteroids, most of which are S-types like itself.

The insights gained from this mission will be crucial for planetary defense research, a top priority for NASA. By April 2, 2029, OSIRIS-APEX will begin imaging Apophis as it catches up to the asteroid.

Earth-based telescopes will also observe Apophis, but following the close encounter, the asteroid will be too near the Sun for ground-based optical telescopes to observe.

This positions OSIRIS-APEX in a unique spot to detect any changes resulting from the encounter.

Studying Apophis up close

Upon arrival on April 13, 2029, OSIRIS-APEX will operate near the asteroid for approximately 18 months. Its mission includes mapping the surface, analyzing its chemical makeup, and conducting a daring maneuver: dipping within 16 feet of Apophis’ surface to stir up rocks and dust, thus revealing the material beneath.

With the rendezvous more than five years away, OSIRIS-APEX’s journey includes six close Sun passes and three gravity assists from Earth, setting it on course for Apophis.

What discoveries lie ahead are yet to be seen, but as Amy Simon poignantly puts it, the mission’s previous achievements at Bennu have only deepened the scientific community’s curiosity and questions for Apophis.

In summary, OSIRIS-APEX’s mission to Apophis is a continuation of its predecessor’s legacy, and also a stride into a realm of new possibilities and discoveries. It offers a glimpse into the formative processes of our solar system and enhancing our understanding of asteroid dynamics and planetary defense.

More about OSIRIS-REx

As mentioned above, the OSIRIS-REx mission, an ambitious endeavor by NASA, marked a significant milestone in space exploration and the study of asteroids.

Launched on September 8, 2016, this mission aimed to reach the near-Earth asteroid Bennu, a carbon-rich body that scientists believe holds clues to the early solar system and the origins of life.

Mission overview and objectives

OSIRIS-REx, an acronym for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, embarked on a journey spanning millions of miles. Its primary objective was to collect and return samples from Bennu’s surface.

This task held immense scientific importance as asteroids like Bennu are remnants from the solar system’s formation, potentially containing organic compounds and water.

Journey to asteroid Bennu

After a two-year journey, OSIRIS-REx reached Bennu in December 2018. The spacecraft then spent two years in close proximity to the asteroid, mapping its surface in unprecedented detail and selecting the most suitable site for sample collection.

This phase involved intricate maneuvers and precise navigation around the asteroid’s small gravitational field.

Historic sample collection

In October 2020, OSIRIS-REx made history by successfully touching down on Bennu’s surface and collecting samples.

The “Touch-And-Go” (TAG) sample acquisition mechanism allowed the spacecraft to briefly contact the asteroid and use a burst of nitrogen gas to stir up regolith (surface material), which was then captured in the sampler head.

Return and landing on Earth

With its precious cargo, OSIRIS-REx began its journey back to Earth in May 2021. NASA’s OSIRIS-REx team then achieved a monumental milestone in space exploration, successfully returning a capsule containing rocks and dust from asteroid Bennu to Earth.

The capsule marked its entry on Earth at 8:52 a.m. MDT on Sunday, landing meticulously in a predetermined area of the Department of Defense’s Utah Test and Training Range, near Salt Lake City.

This event marked the first time NASA has retrieved samples from an asteroid, providing invaluable material for research that could revolutionize our understanding of the solar system and life’s beginnings.

More about asteroid Apophis

As discussed above, asteroid Apophis, named after the ancient Egyptian god of darkness and chaos, is “famous” for an asteroid due to its close approaches to Earth.

Discovered in 2004, this near-Earth asteroid measures approximately 370 meters in diameter, making it one of the most significant known asteroids due to its size and proximity to our planet.

Solar orbit of asteroid Apophis

In its orbit around the sun, Apophis periodically crosses Earth’s path, leading to several close encounters. The most notable of these will occur in 2029, when Apophis will pass within just 31,000 kilometers of Earth’s surface.

This distance, closer than some of our own satellites, will allow astronomers and the public to observe the asteroid with unprecedented clarity.

Scientists initially expressed concerns about the possibility of a collision with Earth in future encounters. However, extensive observations and calculations have lowered this risk probability for at least the next 100 years.

Near-Earth objects

This research provides crucial insights into the trajectory and physical characteristics of Apophis, enhancing our understanding of near-Earth objects (NEOs).

NASA and other space agencies closely monitor Apophis, using it as an opportunity to test and refine planetary defense strategies.

These efforts include tracking the asteroid’s path, analyzing its composition, and developing potential methods to deflect threatening NEOs in the future.

In summary, asteroid Apophis serves as a reminder of our dynamic solar system and the importance of continuous monitoring of near-Earth objects. Its regular appearances near our planet provide valuable opportunities for scientific research and planetary defense preparedness, ensuring that we remain vigilant and equipped to handle potential asteroid threats.

More about asteroid Bennu

As discussed in the beginning of this article, asteroid Bennu, a near-Earth object discovered in 1999, captures the fascination of scientists and astronomers worldwide. Orbiting the sun every 1.2 years, this carbonaceous asteroid offers invaluable insights into the early solar system, the origins of water and organic molecules on Earth, and the potential hazards asteroids can pose to our planet.

Bennu’s origins and composition

Bennu originated from the remnants of a larger asteroid’s destruction in the main asteroid belt between Mars and Jupiter. This ancient relic, approximately 490 meters in diameter, is rich in carbon, making it a prime candidate for studying the building blocks of life. Its surface features boulders, craters, and a remarkable spinning-top shape, attributed to its rapid rotation.

OSIRIS-REx Mission

As discussed above, NASA launched the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) spacecraft in 2016. The mission aimed to map the asteroid, study its composition, and return a sample to Earth for detailed analysis. In October 2020, OSIRIS-REx successfully touched down on Bennu, collecting dust and pebbles in an event marking a significant milestone in space exploration.

Journey home

The spacecraft is set to return to Earth with its precious cargo in 2023, promising to shed light on the mysteries of our solar system’s formation and early history. The samples from Bennu could provide evidence of water and organic materials that are essential for life, offering clues about how these substances were delivered to Earth.

Asteroid Bennu’s future trajectory

Bennu’s orbit brings it close to Earth every six years, making it a potentially hazardous asteroid. Calculations suggest a slight chance of impact with Earth in the late 22nd century. However, the data collected by OSIRIS-REx will help scientists refine Bennu’s trajectory and assess the risk it poses, enhancing our ability to predict and, if necessary, mitigate asteroid threats.

Asteroid Bennu stands as a beacon in our quest to understand the cosmos. Through the lens of the OSIRIS-REx mission, we glimpse the primordial materials that shaped our world and the forces that continue to sculpt the universe. As we await the return of the asteroid samples, the anticipation builds for the new frontiers of knowledge they will unlock.


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