What if Earth's gravity was 4/5ths the strength of Earth's gravity?

We live in a world, where the mass of Earth has been decreased by 1/5th. The mass of the Earth is 5.972 x 10^24 kilograms (give or take 1 kilogram). In this world, the mass of the Earth is 4.777 x 10^24 kilograms. <br><br>How does this change the Earth? By decreasing the mass of the Earth, this planet has less gravity. The strength of a planet's gravity is based on its mass. So, a planet with more mass, such as Jupiter, will have stronger gravity. A planet with less mass, like Mars, will have less gravity.<br><br>The decreased mass of the Earth will also decrease its escape velocity. So, the decreased gravity and decreased escape velocity due to less mass, will cause an increase in atmospheric loss.<br><br>By decreasing the mass of Earth, this planet will have a weaker magnetic field. The core of the Earth is where the magnetic field is produced. The Earth's core has enough iron to create a strong enough magnetic field to protect the Earth from solar flares. Due to the weaker magnetic field of this planet, this planet may be more "exposed" to solar flares. <br><br>So, how would life adapt to a planet with weaker gravity? This question has many different answers, since the effects of weaker gravity on life would vary depending on the species of life. Some life may thrive on this planet, while other life forms may go extinct. This planet may favor the evolution of taller life forms with less massive body parts, such as a smaller brain.<br><br>You can help finish this list, by mentioning what else would change about the Earth, if its mass was decreased by 1/5th.