Asteroid 99942 Apophis: What You Need to Know

Introduction

Asteroid 99942 Apophis is a near-Earth object (NEO) measuring about 1,100 feet (335 meters) across. Initially identified as a potential threat to Earth, further observations have clarified its orbit and confirmed that it poses no risk for at least the next 100 years.

credit goes to NASA

Discovery and Early Concerns

• Discovery: Apophis was discovered on June 19, 2004, by astronomers Roy Tucker, David Tholen, and Fabrizio Bernardi at the Kitt Peak National Observatory in Tucson, Arizona.
• Initial Impact Risk: When first discovered, Apophis was considered one of the most dangerous asteroids due to its potential to impact Earth. Early predictions indicated a close approach in 2029.

Updated Risk Assessments

• 2029 Close Approach: Apophis will pass very close to Earth on April 13, 2029, coming within 20,000 miles (32,000 kilometers) of the planet's surface. This is closer than some satellites.
• Further Observations: Additional observations ruled out any impact risk in 2029, as well as in 2036. A small risk remained for 2068 until precise radar observations in March 2021 eliminated this possibility.
• Current Status: As of now, there is no risk of Apophis impacting Earth for at least the next 100 years.

Observation and Analysis

• Radar Observations: In March 2021, radar observations refined Apophis' orbit with extreme precision, confirming it won't pose a threat.
• Ongoing Studies: Astronomers are using these observations to learn more about Apophis' shape, rotation, and other characteristics.

Apophis in 2029

• Close Approach: During its 2029 flyby, Apophis will be visible from the ground in the Eastern Hemisphere without the need for telescopes.
• Scientific Opportunity: This event provides a unique chance for scientists to study a near-Earth object up close.

NASA's OSIRIS-APEX Mission

• Mission Overview: NASA's OSIRIS-REx spacecraft, after completing its mission to asteroid Bennu, will be redirected to study Apophis in 2029 under the new name OSIRIS-APophis EXplorer (OSIRIS-APEX).
• Objectives: The mission will closely observe Apophis, study changes caused by its Earth flyby, and gather detailed data about its surface and composition.

Apophis' Characteristics

• Size and Distance: Apophis is about 1,100 feet (340 meters) wide and will pass within 19,794 miles (31,860 kilometers) of Earth in 2029.
• Orbit and Rotation: Apophis' orbit crosses Earth's orbit, completing a journey around the Sun in less than one year. Its close encounter in 2029 will alter its orbit, changing its classification from an Aten to an Apollo asteroid.
• Structure: Apophis is likely an S-type (stony) asteroid, made of silicate materials and metals, possibly with a peanut-like shape due to its two lobes.

Conclusion

Asteroid 99942 Apophis, once considered a significant threat, is now understood to be no risk to Earth for at least the next century. The upcoming close approach in 2029 offers an unprecedented opportunity for scientific observation and discovery.

FAQ: Asteroid 99942 Apophis

Introduction

Asteroid 99942 Apophis is a near-Earth object (NEO) measuring about 1,100 feet (335 meters) across. Initially identified as a potential threat to Earth, further observations have clarified its orbit and confirmed that it poses no risk for at least the next 100 years.

Discovery and Early Concerns

Q1: When and by whom was Apophis discovered?

A1: Apophis was discovered on June 19, 2004, by astronomers Roy Tucker, David Tholen, and Fabrizio Bernardi at the Kitt Peak National Observatory in Tucson, Arizona.

Q2: Why was Apophis considered dangerous when first discovered?

A2: It was considered one of the most hazardous asteroids because early predictions indicated a close approach to Earth in 2029, raising concerns about a possible impact.

Updated Risk Assessments

Q3: How close will Apophis come to Earth in 2029?

A3: Apophis will pass within 20,000 miles (32,000 kilometers) of Earth's surface on April 13, 2029. This distance is closer than some satellites orbiting the Earth.

Q4: What do recent observations say about the risk of Apophis impacting Earth?

A4: Observations have ruled out any impact risk in 2029 and 2036. Precise radar observations in March 2021 eliminated the small risk for 2068. There is no risk for at least the next 100 years.

Observation and Analysis

Q5: What were the key findings from the radar observations in March 2021?

A5: The radar observations refined Apophis' orbit with extreme precision, confirming it won't pose a threat to Earth.

Q6: What ongoing studies are being conducted on Apophis?

A6: Astronomers are using radar and other observations to learn more about Apophis' shape, rotation, and other characteristics. Apophis in 2029

Q7: Will Apophis be visible from Earth during its 2029 flyby?

A7: Yes, during its 2029 flyby, Apophis will be visible from the ground in the Eastern Hemisphere without the need for telescopes.

Q8: Why is the 2029 flyby significant for scientists?

A8: It provides a unique opportunity for scientists to study a near-Earth object up close, enhancing our understanding of such asteroids.

NASA's OSIRIS-APEX Mission

Q9: What is the OSIRIS-APEX mission?

A9: NASA's OSIRIS-REx spacecraft, after completing its mission to asteroid Bennu, will study Apophis in 2029 under the new name OSIRIS-APophis EXplorer (OSIRIS-APEX).

Q10: What are the objectives of the OSIRIS-APEX mission?

A10: The mission aims to closely observe Apophis, study changes caused by its Earth flyby, and gather detailed data about its surface and composition.

Apophis' Characteristics

Q11: How big is Apophis?

A11: Apophis is about 1,100 feet (340 meters) wide.

Q12: What is unique about Apophis' orbit and rotation?

A12: Apophis' orbit crosses Earth's orbit and completes a journey around the Sun in less than one year. Its close encounter in 2029 will alter its orbit, changing its classification from an Aten to an Apollo asteroid. Apophis likely has a peanut-like shape due to its two lobes.

Conclusion Asteroid 99942 Apophis, once considered a significant threat, is now understood to pose no risk to Earth for at least the next century. The upcoming close approach in 2029 offers an unprecedented opportunity for scientific observation and discovery.

References