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.

  1. How do astronomers find planets around other stars?
  2. What is the unemployment rate in each country?

Chart 1 of 2 · Space

How do astronomers find planets around other stars?

The interactive chart needs JavaScript. The numbers are on the chart's page.

As of November 2026, 4,785 of the 6,451 confirmed exoplanets, about 74%, were found by the transit method: a telescope sees a star dim slightly as a planet passes in front of it. Radial velocity, which spots a star's slight wobble as a planet tugs on it, found 1,204. Only 98 have been photographed directly (imaging).

Questions to discuss

  1. In one sentence of your own, what does this chart show?
  2. Find the biggest change or difference in the chart. What might explain it?
  3. Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?

Source: NASA Exoplanet Archive, Planetary Systems Composite Data (Public domain (NASA data); this research has made use of the NASA Exoplanet Archive, operated by Caltech under contract with NASA) · Data as of Nov 4, 2026

Open the chart and its numbers

Chart 2 of 2 · World

What is the unemployment rate in each country?

The interactive chart needs JavaScript. The numbers are on the chart's page.

In 2025, 4.2% of workers in the United States were unemployed, against 4.8% worldwide; the highest rate was 34.2% in Eswatini, and the lowest 0.1%, in Qatar. Search 182 countries and territories. These are the International Labour Organization's estimates, which count people without work who are looking for it and fill gaps where a country runs no regular survey, so they can differ from a country's own figures.

How to read this chart

Each bar is the share of a country's workers who have no job and are looking for one, estimated by the International Labour Organization. The dashed line is the world. People who aren't looking for work, such as students and retirees, aren't counted as unemployed at all.

Questions to discuss

  1. Is the United States above or below the world rate, and by about how many percentage points?
  2. A country can have low unemployment while many people earn very little. How is that possible?
  3. Why would someone who has given up looking for work not count as unemployed? Does that make the number more or less useful?

Teachers: make your own chart assignment, or change this one. Free, no account needed.