... The North Pole of Mars is capped by layers likely consisting of ice and dust deposited over millions of years. ... M61: Virgo Spiral Galaxy . ... Visible in M61 are a host of features common to spiral galaxies: bright spiral arms, a central bar, dust lanes, and bright knots of stars. ... Prominent features include a small open cluster of stars, a diffuse red-glowing emission nebula, large lanes of obscuring gas and dust, and dense knots of dust and gas in which stars may still be forming. ...