Northern lights may once again be visible deep into mid latitudes tonight as geomagnetic storm conditions continue to wreak havoc with Earth's magnetic field.
The search for life on other worlds needs a way to sift through the chemistry of their atmospheres. If another species observed Earth to search for life, they'd look for "smoking gun" chemistry in the atmosphere. That includes looking for oxygen, since it is created through photosynthesis by plants and some bacteria. So, the key is to look for life-dependent chemical "signals" at exoplanets.