diff --git a/sources/01-overview.md b/sources/01-overview.md
index d92da49..68dbb27 100644
--- a/sources/01-overview.md
+++ b/sources/01-overview.md
@@ -4,4 +4,6 @@ The first chapter contains notebooks that document the data retrieval process fr
 
 It explains how to use the [`sentinelsat`](https://github.com/sentinelsat/sentinelsat) library to interact with the HTTP API: How to specify what kind of data we are interested in with the aide of open map data from [OpenStreetMap](https://www.openstreetmap.org/) and [`geopandas`](https://geopandas.org/) and how to download it. It then goes on to show how to use [`rasterio`](https://rasterio.readthedocs.io/) and [`numpy`](https://numpy.org/) to read and process the downloaded data and [`matplotlib`](https://matplotlib.org/stable/index.html) to visualize it.
 
-The Sentinel-2 satellite captures light in visible and invisible parts of the spectrum. This can be used to derive different kinds of useful information about ground-level phenomena. The end of this chapter will detail how to use it to create true color images for different moments in time.
+The Sentinel-2 mission is a part of the [Copernicus earth observation missions of the ESA](http://www.esa.int/Applications/Observing_the_Earth/Copernicus), which provide open satellite data to anyone. Sentinel-2 is a group of satellites that capture electromagnetic radiation. A part of this is visible light, so it can be used to create detailed satellite maps, but a large part of this is invisible. It can be used to infer information on all kinds of ground-level phenomena where other data sources are scarce
+
+This chapter will detail how to retrieve, interpret and manipulate this data, and ends with a notebook that can create a true color image using recent satellite data for any area.
diff --git a/sources/01d-true-color-mosaic.ipynb b/sources/01d-true-color-mosaic.ipynb
index 153477a..7efaf37 100644
--- a/sources/01d-true-color-mosaic.ipynb
+++ b/sources/01d-true-color-mosaic.ipynb
@@ -368,8 +368,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "These are the same products in a table.\n",
-    "You can use the table to find out information about the exact capture time."
+    "These are the same products in a table, which contains useful information such as the exact capture time (in the `beginposition` column)."
    ]
   },
   {