Why so many asteroid close approaches lately?

Every month about 40 known or recently discovered asteroids come within 0.05 astronomical units, or about 19 lunar radii, from our planet. In some cases, such as in the month of December 2016, four or even five objects reach their closest approach distance on the same day. Clusters of asteroid flybys often attracts the interest of the media and of the public, but are these occurrences unusual?

Upon applying statistical considerations to the present discovery rate and assuming a uniform probability of discovery every day, it turns out that they are not. A cluster of at least four objects approaching on the same day is expected about three months every four; a cluster of five about three times per year.

In reality, the groupings are likely to happen even more often. It is well known that astronomical observations peak around new Moon, when the sky is darker. Therefore asteroids flying-by near full Moon, while equally common, are more likely to go undiscovered and therefore not be included in the counts. (ESA NEO Newsletter February 2017)

Also new technologies and studies are playing a role. Although it might seem there are a lot more asteroids than before, this isn’t the case, we’re just getting better at finding them.

asteroid close approaches asteroid flybys

Some facts presented by NASA:

Every day, Earth is bombarded with more than 100 tons of dust and sand-sized particles.

About once a year, an automobile-sized asteroid hits Earth’s atmosphere, creates an impressive fireball, and burns up before reaching the surface.

Every 2,000 years or so, a meteoroid the size of a football field hits Earth and causes significant damage to the area.

Only once every few million years, an object large enough to threaten Earth’s civilization comes along. Impact craters on Earth, the moon and other planetary bodies are evidence of these occurrences.

Space rocks smaller than about 25 meters (about 82 feet) will most likely burn up as they enter the Earth’s atmosphere and cause little or no damage.

The NEOShield-2 Outreach School Project in Israel

Reported by Victor Bar, NEOShield-2 Agent in Israel

At the beginning of the school year, a first of its kind project has began for the 8th grade gifted students of Ahad Haam Junior High School at the city of Petach-Tikva in Israel, the asteroid threat and mitigation measures based on the NEOShield-2 project.

After having an online meeting with the school principal manager, teachers, parents and the NEOShield-2 Public Outreach coordinator, we created the project format and started to develop it.

It started with my initial lecture about asteroids in general: type of asteroids, orbits types, their place of origin, and famous impact events. Then I introduced the NEOShield-2 project, its purpose, the technologies researched and developed with a special emphasis on asteroid mitigation techniques.

After the initial lecture, the children were divided into several groups. Each group explored further the topic using the internet and submitted their conclusion into the class info repository, so that all the other groups could benefit from their findings.

Orly Alperin, the planetary science teacher and the school coordinator for this project, continued teaching the children​ about different aspects of asteroids and strengthening their knowledge, while Ido Adiv, the physics teacher discussed physics matters such as Keplers laws, Spectoroscopy and Newton’s laws.

Following the lessons I came for a final lecture before starting to work on the spacecraft models. I discussed spacecraft engineering concepts with them.

After the lecture, the children began designing their spacecraft models.

After completing their models, they were displayed at the Ramon Space Education Exhibition in Bar Ilan University during the Israeli Space Week.

We even got a special visit from Rona Ramon, the widow of the late Ilan Ramon, the 1st Israeli astronaut and a member of STS107.

NEOShield-2 note:

The NEOShield-2 Team is very proud of our agent Victor Bar who did not measure efforts to organize and develop this incredible project. We truly hope to see more events like this one around the world spreading the asteroid impact awareness.

Are you also interested in becoming a NEOShield-2 agent? Check more information here.