Starship Asterisk*

The background galaxy is highly redshifted (z = 2.379; object is 18.8 billion ly away, light was emitted 10.9 billion years ago). Just because something is redshifted, that doesn't mean it will necessarily appear red. Keep in mind that while blue light is shifted towards red, red light disappears i...

guys, help me out here. My understanding of the lensing effect requires great distance between us and the lensed object. If that understanding is correct, why isn't the horseshoe significantly red-shifted?

It is my understanding that habitable zone is dependent on many factors, many related to the planetary body itself, such as the gravity of the planet, it's magnetic field, density of atmosphere and proximity to other large bodies. For example, Mars doesn't have a protective magnetic field and gravit...