The Whirlpool Galaxy, also known as Messier 51 or M51, is familiar to legions of amateur astronomers, a face on spiral gravitationally interacting with a smaller nearby galaxy. On clear, moonless nights, M51’s spiral shape can be discerned in relatively modest amateur instruments, a dim, ghostly body near the bright star Alkaid at the end of the Big Dipper’s handle. But through the Hubble Space Telescope, M51 is revealed in all of its jaw dropping splendour, a magnificent swirl of tightly-wound spiral arms, glowing regions of star formation and countless clusters. Gravitational interactions with the companion galaxy, not seen in this image of the Whirlpool’s heart, trigger star formation across M51 as seen here in bright clusters of energetic young stars highlighted in red. Also visible are numerous dust “spurs” extending away from the spiral arms in near perpendicular fashion. The origin and evolution of the spurs are not yet understood.
This NASA/ESA Hubble Space Telescope image shows the globular cluster NGC 1854, a gathering of white and blue stars in the southern constellation of Dorado. NGC 1854 is located about 135,000 light-years away, in the Large Magellanic Cloud (LMC), one of our closest cosmic neighbours and a satellite galaxy of the Milky Way.
At first glance, this cosmic kaleidoscope of purple, blue and pink offers a strikingly beautiful — and serene — snapshot of the cosmos. However, this multi-coloured haze actually marks the site of two colliding galaxy clusters, forming a single object known as MACS J0416.1-2403 (or MACS J0416 for short), 4.3 billion light-years away from Earth.
This NASA/ESA Hubble Space Telescope image shows the galaxy Messier 94, which lies in the small northern constellation of Canes Venatici (the Hunting Dogs), about 16 million light-years away. Within the bright ring or starburst ring around Messier 94, new stars are forming at a high rate and many young, bright stars are present within it.