For a few years, we have known that the universe is in a constant expansion that is accelerating over time. This causes the space that is between two objects is increasing. In other words, it seems that everything is moving away indefinitely. However, that is not the case for a specific galaxy, as it is surprisingly getting closer to us.
This is what NASA recently reported. The space agency said that using the Hubble telescope; it was discovered that the Messier 90 galaxy is getting closer and closer to us. This goes against everything we knew, believing that objects were only moving away.
Messier 90 is about 60 million light years from the Milky Way, in the constellation of Virgo. The galaxy lies within the Virgo cluster, composed of more than 1,200 of its counterparts.
How was this displacement discovered with such security? The truth is that one of the cameras of the Hubble telescope has been tracking it since 1994 and did so until 2010. It obtained images using four light detectors, including infrared, ultraviolet and visible-spectrum light. These images usually overlap, but one of them was more extensive and had to be adjusted to be on par with the others.
What happened was a phenomenon called “blueshift” or “blue shift”. This occurs when an object that emanates light moves towards us, causing a change in the frequency of the waves. Thus, the colour of the light ends up being in a blue spectrum. The opposite occurs with objects that move away, causing a frequency that tends to read. With this, it was discovered that the Messier 90 galaxy is moving towards us.
For NASA, the explanation is that this unusual movement is not clear. According to certain astronomers, it is likely that the colossal mass of the Virgo cluster is pushing some of its members at high speeds. This is a significant displacement because it involves moving faster than the expansion speed of the universe.