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NASA Picture Of The Day

Welcome to Perihelion

rth's orbit around the Sun is not a circle, it's an ellipse. The point along its elliptical orbit where our fair planet is closest to the Sun is called perihelion. This year perihelion is today, January 4, at 13:28 UTC, with the Earth about 147 million kilometers from the Sun. For comparison, at aphelion on last July 3 Earth was at its farthest distance from the Sun, some 152 million kilometers away. But distance from the Sun doesn't determine Earth's seasons. It's only by coincidence that the beginning of southern summer (northern winter) on the December solstice - when this H-alpha picture of the active Sun was taken - is within 14 days of Earth's perihelion date. And it's only by coincidence that Earth's perihelion date is within 11 days of the historic perihelion of NASA's Parker Solar Probe. Launched in 2018, the Parker Solar Probe flew within 6.2 million kilometers of the Sun's surface on 2024 December 24, breaking its own record for closest perihelion for a spacecraft from planet Earth.

Date image released: 2025-01-04

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Chelsea 1y ago

Here is the summary and key points from the NASA Picture of the Day:

**Summary:** Today, January 4, marks perihelion, the point in Earth's elliptical orbit around the Sun where our planet is closest to the Sun. This year, Earth is about 147 million kilometers away from the Sun.

**Key Points:**

1. **Perihelion**: The point of closest approach between Earth and the Sun.

2. **Distance from the Sun**: January 4 marks perihelion, with Earth at approximately 147 million kilometers from the Sun.

3. **Comparison to aphelion**: Last July 3 marked aphelion, where Earth was at its farthest distance from the Sun (approximately 152 million kilometers away).

4. **Seasons and perihelion**: The beginning of southern summer (northern winter) on the December solstice is coincidentally close to Earth's perihelion date.

5. **Parker Solar Probe**: Launched in 2018, this spacecraft flew within 6.2 million kilometers of the Sun's surface on December 24, 2024, setting a record for closest perihelion.

**Image:** The featured image is an H-alpha picture of the active Sun taken around the December solstice.