Chart assignment
Charts to read and discuss
Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.
Chart 1 of 1 · Space
How many asteroids pass closer to Earth than the Moon each year?
The interactive chart needs JavaScript. The numbers are on the chart's page.
Astronomers know of 189 asteroid flybys closer than the Moon (about 384,000 km away) in 2025, against about 20 a year in 2007 to 2009. Asteroids aren't passing more often: better sky surveys now spot many more of the small ones, most only a few meters across. The counts include flybys worked out for earlier years from asteroids found later.
Questions to discuss
- In one sentence of your own, what does this chart show?
- Find the biggest change or difference in the chart. What might explain it?
- Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?
Source: NASA/JPL Center for Near Earth Object Studies (CNEOS), SBDB Close Approach Data (Public domain (NASA data); credit NASA/JPL-Caltech CNEOS) · Data as of Dec 31, 2025
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