Astronomy Escape Velocity

Written by Aarav Sharma, Mathematics Editor Reviewed by Vikram Sen, Technical Reviewer Last updated: June 1, 2026 Last verified: June 1, 2026 · Methodology · Accuracy policy

A gravitational-binding KPI. Distinct from orbital circular speed and from Physics velocity (d/t).

v = square root of (2GM/R) in m/s.

Tip: Keep “Mass M (kg)” and “Radius R (m)” on the same basis (period, units, and population) before calculating Astronomy Escape Velocity.

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Escape speed from the surface of a spherical body is the square root of 2GM/R.

Enter mass (kg) and radius (m). Uses G = 6.6743×10⁻¹¹.

Escape Velocity

Understanding Astronomy Escape Velocity

How we calculate. v = square root of (2GM/R) in m/s. The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.

Real-world scenario: A typical Astronomy Escape Velocity case uses mass m (kg) 5.97e24 and radius r (m) 6.37e6. Enter the same figures below to reproduce the worked path.

What is Astronomy Escape Velocity?

A gravitational-binding KPI. Distinct from orbital circular speed and from Physics velocity (d/t).

SI units
Non-relativistic teaching model
From surface radius R

The Formula

Escape Velocity

v = √(2 G M ÷ R)

Worked Example

Scenario: M = 5.97×10²⁴ kg; R = 6.37×10⁶ m.

Step 1: 2GM/R ≈ 1.25×10⁸

Step 2: √ ≈ 11180

Answer: Escape velocity is approximately 11180 m/s.

Common Use Cases

Homework: planetary escape
Study: pair with surface gravity
Lab: SI checks

Pro Tips

Result in m/s
Convert if you need km/s
Not rocket Δv budgets

Limitations: Astronomy Escape Velocity results are educational astronomy study aids—not navigation, mission planning, or professional observing advice. Confirm constants and units with your textbook or instructor.

FAQ

Same as orbital speed?

Circular orbital speed is √(GM/R); escape is √(2GM/R).

Same as Physics velocity?

No. Physics velocity on this site is distance÷time.

Authoritative References

For astronomy study concepts, consult:

OpenStax Astronomy — free textbook reference
NASA — mission and outreach context
IAU — astronomical constants and naming