✓ NASAScience & Systems
NGC 4654's lopsided spiral arms trace two competing galactic forces
Two cosmic forces shaped NGC 4654: ram pressure from racing through intergalactic gas, and a near-miss with a neighbour 500 million years ago.
NGC 4654, 72 million light-years away, races through Virgo Cluster gas that squeezes one side and drags a tail from the other. A nearby galaxy flew past about 500 million years ago and stripped gas from one flank, halting star formation there.
Both forces created the lopsided shape Hubble has captured. The galaxy still forms nearly two Sun-sized stars every year.
- 72 million light-years away
- Distance
- Virgo Cluster, constellation Virgo
- Location
- NGC 4639 fly-by 500 million years ago
- Galaxy interaction
- nearly two Suns per year
- Star formation rate
Why it mattersThe images help scientists understand what stops galaxies from forming stars, which could reveal the eventual fate of our own Milky Way.
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